feat: add configurable speed and expanded grid presets for snake

- Add per-game speed setting with presets (Slow/Normal/Fast/Insane)
- Add speed selector UI in snake lobby
- Expand grid presets with Tiny (15x15) and XL (50x30)
- Auto-calculate cell size based on grid dimensions
- Preserve speed setting in rematch games

db/gen/games.sql.go

@@ -13,7 +13,7 @@ import (
 const createGame = `-- name: CreateGame :one
 INSERT INTO games (id, board, current_turn, status)
 VALUES (?, ?, ?, ?)
-RETURNING id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score
+RETURNING id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score, snake_speed
 `
 
 type CreateGameParams struct {
@@ -47,6 +47,7 @@ func (q *Queries) CreateGame(ctx context.Context, arg CreateGameParams) (Game, e
 		&i.MaxPlayers,
 		&i.GameMode,
 		&i.Score,
+		&i.SnakeSpeed,
 	)
 	return i, err
 }
@@ -87,7 +88,7 @@ func (q *Queries) DeleteGame(ctx context.Context, id string) error {
 }
 
 const getActiveGames = `-- name: GetActiveGames :many
-SELECT id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score FROM games WHERE game_type = 'connect4' AND status < 2
+SELECT id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score, snake_speed FROM games WHERE game_type = 'connect4' AND status < 2
 `
 
 func (q *Queries) GetActiveGames(ctx context.Context) ([]Game, error) {
@@ -115,6 +116,7 @@ func (q *Queries) GetActiveGames(ctx context.Context) ([]Game, error) {
 			&i.MaxPlayers,
 			&i.GameMode,
 			&i.Score,
+			&i.SnakeSpeed,
 		); err != nil {
 			return nil, err
 		}
@@ -130,7 +132,7 @@ func (q *Queries) GetActiveGames(ctx context.Context) ([]Game, error) {
 }
 
 const getGame = `-- name: GetGame :one
-SELECT id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score FROM games WHERE id = ?
+SELECT id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score, snake_speed FROM games WHERE id = ?
 `
 
 func (q *Queries) GetGame(ctx context.Context, id string) (Game, error) {
@@ -152,6 +154,7 @@ func (q *Queries) GetGame(ctx context.Context, id string) (Game, error) {
 		&i.MaxPlayers,
 		&i.GameMode,
 		&i.Score,
+		&i.SnakeSpeed,
 	)
 	return i, err
 }
@@ -192,7 +195,7 @@ func (q *Queries) GetGamePlayers(ctx context.Context, gameID string) ([]GamePlay
 }
 
 const getGamesByUserID = `-- name: GetGamesByUserID :many
-SELECT g.id, g.board, g.current_turn, g.status, g.winner_user_id, g.winning_cells, g.created_at, g.updated_at, g.rematch_game_id, g.game_type, g.grid_width, g.grid_height, g.max_players, g.game_mode, g.score FROM games g
+SELECT g.id, g.board, g.current_turn, g.status, g.winner_user_id, g.winning_cells, g.created_at, g.updated_at, g.rematch_game_id, g.game_type, g.grid_width, g.grid_height, g.max_players, g.game_mode, g.score, g.snake_speed FROM games g
 JOIN game_players gp ON g.id = gp.game_id
 WHERE gp.user_id = ?
 ORDER BY g.updated_at DESC
@@ -223,6 +226,7 @@ func (q *Queries) GetGamesByUserID(ctx context.Context, userID sql.NullString) (
 			&i.MaxPlayers,
 			&i.GameMode,
 			&i.Score,
+			&i.SnakeSpeed,
 		); err != nil {
 			return nil, err
 		}

db/gen/models.go

@@ -24,6 +24,7 @@ type Game struct {
 	MaxPlayers    int64
 	GameMode      int64
 	Score         int64
+	SnakeSpeed    int64
 }
 
 type GamePlayer struct {

db/gen/snake_games.sql.go

@@ -11,9 +11,9 @@ import (
 )
 
 const createSnakeGame = `-- name: CreateSnakeGame :one
-INSERT INTO games (id, board, current_turn, status, game_type, grid_width, grid_height, max_players, game_mode)
+INSERT INTO games (id, board, current_turn, status, game_type, grid_width, grid_height, max_players, game_mode, snake_speed)
-VALUES (?, ?, 0, ?, 'snake', ?, ?, 8, ?)
+VALUES (?, ?, 0, ?, 'snake', ?, ?, 8, ?, ?)
-RETURNING id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score
+RETURNING id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score, snake_speed
 `
 
 type CreateSnakeGameParams struct {
@@ -23,6 +23,7 @@ type CreateSnakeGameParams struct {
 	GridWidth  sql.NullInt64
 	GridHeight sql.NullInt64
 	GameMode   int64
+	SnakeSpeed int64
 }
 
 func (q *Queries) CreateSnakeGame(ctx context.Context, arg CreateSnakeGameParams) (Game, error) {
@@ -33,6 +34,7 @@ func (q *Queries) CreateSnakeGame(ctx context.Context, arg CreateSnakeGameParams
 		arg.GridWidth,
 		arg.GridHeight,
 		arg.GameMode,
+		arg.SnakeSpeed,
 	)
 	var i Game
 	err := row.Scan(
@@ -51,6 +53,7 @@ func (q *Queries) CreateSnakeGame(ctx context.Context, arg CreateSnakeGameParams
 		&i.MaxPlayers,
 		&i.GameMode,
 		&i.Score,
+		&i.SnakeSpeed,
 	)
 	return i, err
 }
@@ -91,7 +94,7 @@ func (q *Queries) DeleteSnakeGame(ctx context.Context, id string) error {
 }
 
 const getActiveSnakeGames = `-- name: GetActiveSnakeGames :many
-SELECT id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score FROM games WHERE game_type = 'snake' AND status < 2 AND game_mode = 0
+SELECT id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score, snake_speed FROM games WHERE game_type = 'snake' AND status < 2 AND game_mode = 0
 `
 
 func (q *Queries) GetActiveSnakeGames(ctx context.Context) ([]Game, error) {
@@ -119,6 +122,7 @@ func (q *Queries) GetActiveSnakeGames(ctx context.Context) ([]Game, error) {
 			&i.MaxPlayers,
 			&i.GameMode,
 			&i.Score,
+			&i.SnakeSpeed,
 		); err != nil {
 			return nil, err
 		}
@@ -134,7 +138,7 @@ func (q *Queries) GetActiveSnakeGames(ctx context.Context) ([]Game, error) {
 }
 
 const getSnakeGame = `-- name: GetSnakeGame :one
-SELECT id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score FROM games WHERE id = ? AND game_type = 'snake'
+SELECT id, board, current_turn, status, winner_user_id, winning_cells, created_at, updated_at, rematch_game_id, game_type, grid_width, grid_height, max_players, game_mode, score, snake_speed FROM games WHERE id = ? AND game_type = 'snake'
 `
 
 func (q *Queries) GetSnakeGame(ctx context.Context, id string) (Game, error) {
@@ -156,6 +160,7 @@ func (q *Queries) GetSnakeGame(ctx context.Context, id string) (Game, error) {
 		&i.MaxPlayers,
 		&i.GameMode,
 		&i.Score,
+		&i.SnakeSpeed,
 	)
 	return i, err
 }

db/migrations/005_add_snake_speed.sql

@@ -0,0 +1,5 @@
+-- +goose Up
+ALTER TABLE games ADD COLUMN snake_speed INTEGER NOT NULL DEFAULT 7;
+
+-- +goose Down
+ALTER TABLE games DROP COLUMN snake_speed;

db/persister.go

@@ -172,6 +172,7 @@ func (p *SnakePersister) SaveSnakeGame(sg *snake.SnakeGame) error {
 			GridWidth:  gridWidth,
 			GridHeight: gridHeight,
 			GameMode:   int64(sg.Mode),
+			SnakeSpeed: int64(sg.Speed),
 		})
 		return err
 	}
@@ -224,6 +225,7 @@ func (p *SnakePersister) LoadSnakeGame(id string) (*snake.SnakeGame, error) {
 		Status:  snake.Status(row.Status),
 		Mode:    snake.GameMode(row.GameMode),
 		Score:   int(row.Score),
+		Speed:   int(row.SnakeSpeed),
 	}
 
 	if row.RematchGameID.Valid {

db/queries/snake_games.sql

@@ -1,6 +1,6 @@
 -- name: CreateSnakeGame :one
-INSERT INTO games (id, board, current_turn, status, game_type, grid_width, grid_height, max_players, game_mode)
+INSERT INTO games (id, board, current_turn, status, game_type, grid_width, grid_height, max_players, game_mode, snake_speed)
-VALUES (?, ?, 0, ?, 'snake', ?, ?, 8, ?)
+VALUES (?, ?, 0, ?, 'snake', ?, ?, 8, ?, ?)
 RETURNING *;
 
 -- name: GetSnakeGame :one

main.go

@@ -152,6 +152,19 @@ func main() {
 			snakeNickname = c.Signal(username)
 		}
 
+		// Speed selection signal (index into SpeedPresets, default to Normal which is index 1)
+		selectedSpeedIndex := c.Signal(1)
+
+		// Speed selector actions
+		var speedSelectClicks []h.H
+		for i := range snake.SpeedPresets {
+			idx := i
+			speedSelectClicks = append(speedSelectClicks, c.Action(func() {
+				selectedSpeedIndex.SetValue(idx)
+				c.Sync()
+			}).OnClick())
+		}
+
 		// Snake create game actions — one per preset for solo and multiplayer
 		var snakeSoloClicks []h.H
 		var snakeMultiClicks []h.H
@@ -163,7 +176,12 @@ func main() {
 					return
 				}
 				c.Session().Set("nickname", name)
-				si := snakeStore.Create(w, ht, snake.ModeSinglePlayer)
+				speedIdx := selectedSpeedIndex.Int()
+				speed := snake.DefaultSpeed
+				if speedIdx >= 0 && speedIdx < len(snake.SpeedPresets) {
+					speed = snake.SpeedPresets[speedIdx].Speed
+				}
+				si := snakeStore.Create(w, ht, snake.ModeSinglePlayer, speed)
 				c.Redirectf("/snake/%s", si.ID())
 			}).OnClick())
 			snakeMultiClicks = append(snakeMultiClicks, c.Action(func() {
@@ -172,7 +190,12 @@ func main() {
 					return
 				}
 				c.Session().Set("nickname", name)
-				si := snakeStore.Create(w, ht, snake.ModeMultiplayer)
+				speedIdx := selectedSpeedIndex.Int()
+				speed := snake.DefaultSpeed
+				if speedIdx >= 0 && speedIdx < len(snake.SpeedPresets) {
+					speed = snake.SpeedPresets[speedIdx].Speed
+				}
+				si := snakeStore.Create(w, ht, snake.ModeMultiplayer, speed)
 				c.Redirectf("/snake/%s", si.ID())
 			}).OnClick())
 		}
@@ -194,6 +217,8 @@ func main() {
 				SnakeSoloClicks:    snakeSoloClicks,
 				SnakeMultiClicks:   snakeMultiClicks,
 				ActiveSnakeGames:   snakeStore.ActiveGames(),
+				SelectedSpeedIndex: selectedSpeedIndex.Int(),
+				SpeedSelectClicks:  speedSelectClicks,
 			})
 		})
 	})

snake/loop.go

@@ -7,8 +7,6 @@ import (
 const (
 	targetFPS                    = 60
 	tickInterval                 = time.Second / targetFPS
-	snakeSpeed                     = 7 // cells per second
-	moveInterval                   = time.Second / snakeSpeed
 	countdownSecondsMultiplayer  = 10
 	countdownSecondsSinglePlayer = 3
 	inactivityLimit              = 60 * time.Second
@@ -114,17 +112,12 @@ func (si *SnakeGameInstance) gamePhase() {
 				return
 			}
 
-			// Apply pending directions every tick for responsive input
+			// Track input activity for inactivity timeout
-			inputReceived := false
 			for i := 0; i < 8; i++ {
-				if si.pendingDir[i] != nil && i < len(si.game.State.Snakes) && si.game.State.Snakes[i] != nil {
+				if len(si.pendingDirQueue[i]) > 0 {
-					si.game.State.Snakes[i].Dir = *si.pendingDir[i]
-					si.pendingDir[i] = nil
-					inputReceived = true
-				}
-			}
-			if inputReceived {
 					lastInput = time.Now()
+					break
+				}
 			}
 
 			// Inactivity timeout
@@ -138,7 +131,14 @@ func (si *SnakeGameInstance) gamePhase() {
 				return
 			}
 
-			// Only advance game state at snakeSpeed
+			// Compute move interval from per-game speed
+			speed := si.game.Speed
+			if speed <= 0 {
+				speed = DefaultSpeed
+			}
+			moveInterval := time.Second / time.Duration(speed)
+
+			// Only advance game state at game speed
 			moveAccum += tickInterval
 			if moveAccum < moveInterval {
 				si.gameMu.Unlock()
@@ -146,6 +146,14 @@ func (si *SnakeGameInstance) gamePhase() {
 			}
 			moveAccum -= moveInterval
 
+			// Pop one direction from queue per movement frame
+			for i := 0; i < 8; i++ {
+				if len(si.pendingDirQueue[i]) > 0 && i < len(si.game.State.Snakes) && si.game.State.Snakes[i] != nil {
+					si.game.State.Snakes[i].Dir = si.pendingDirQueue[i][0]
+					si.pendingDirQueue[i] = si.pendingDirQueue[i][1:]
+				}
+			}
+
 			state := si.game.State
 
 			// Advance snakes

snake/store.go

@@ -47,7 +47,10 @@ func (ss *SnakeStore) makeNotify(gameID string) func() {
 	}
 }
 
-func (ss *SnakeStore) Create(width, height int, mode GameMode) *SnakeGameInstance {
+func (ss *SnakeStore) Create(width, height int, mode GameMode, speed int) *SnakeGameInstance {
+	if speed <= 0 {
+		speed = DefaultSpeed
+	}
 	id := generateID(4)
 	sg := &SnakeGame{
 		ID: id,
@@ -58,6 +61,7 @@ func (ss *SnakeStore) Create(width, height int, mode GameMode) *SnakeGameInstanc
 		Players: make([]*Player, 8),
 		Status:  StatusWaitingForPlayers,
 		Mode:    mode,
+		Speed:   speed,
 	}
 	si := &SnakeGameInstance{
 		game:      sg,
@@ -160,7 +164,7 @@ func (ss *SnakeStore) ActiveGames() []*SnakeGame {
 type SnakeGameInstance struct {
 	game           *SnakeGame
 	gameMu         sync.RWMutex
-	pendingDir [8]*Direction
+	pendingDirQueue [8][]Direction // queued directions per slot (max 3)
 	notify         func()
 	persister      Persister
 	store          *SnakeStore
@@ -231,8 +235,8 @@ func (si *SnakeGameInstance) Join(player *Player) bool {
 	return true
 }
 
-// SetDirection buffers a direction change for the given slot.
+// SetDirection queues a direction change for the given slot.
-// The write happens under the game lock to avoid a data race with the game loop.
+// Validates against the last queued direction (or current snake dir) to prevent 180° turns.
 func (si *SnakeGameInstance) SetDirection(slot int, dir Direction) {
 	if slot < 0 || slot >= 8 {
 		return
@@ -240,13 +244,28 @@ func (si *SnakeGameInstance) SetDirection(slot int, dir Direction) {
 	si.gameMu.Lock()
 	defer si.gameMu.Unlock()
 
-	if si.game.State != nil && slot < len(si.game.State.Snakes) {
+	if si.game.State == nil || slot >= len(si.game.State.Snakes) {
-		s := si.game.State.Snakes[slot]
-		if s != nil && s.Alive && !ValidateDirection(s.Dir, dir) {
 		return
 	}
+	s := si.game.State.Snakes[slot]
+	if s == nil || !s.Alive {
+		return
 	}
-	si.pendingDir[slot] = &dir
+
+	// Validate against last queued direction, or current snake direction if queue empty
+	refDir := s.Dir
+	if len(si.pendingDirQueue[slot]) > 0 {
+		refDir = si.pendingDirQueue[slot][len(si.pendingDirQueue[slot])-1]
+	}
+	if !ValidateDirection(refDir, dir) {
+		return
+	}
+
+	// Cap queue at 3 to prevent unbounded growth
+	if len(si.pendingDirQueue[slot]) >= 3 {
+		return
+	}
+	si.pendingDirQueue[slot] = append(si.pendingDirQueue[slot], dir)
 }
 
 func (si *SnakeGameInstance) Stop() {
@@ -272,9 +291,10 @@ func (si *SnakeGameInstance) CreateRematch() *SnakeGameInstance {
 	width := si.game.State.Width
 	height := si.game.State.Height
 	mode := si.game.Mode
+	speed := si.game.Speed
 	si.gameMu.Unlock()
 
-	newSI := si.store.Create(width, height, mode)
+	newSI := si.store.Create(width, height, mode, speed)
 	newID := newSI.ID()
 
 	si.gameMu.Lock()

snake/types.go

@@ -97,8 +97,24 @@ type SnakeGame struct {
 	RematchGameID *string
 	Mode          GameMode // ModeMultiplayer or ModeSinglePlayer
 	Score         int      // tracks food eaten in single player
+	Speed         int      // cells per second
 }
 
+// Speed presets
+type SpeedPreset struct {
+	Name  string
+	Speed int
+}
+
+var SpeedPresets = []SpeedPreset{
+	{Name: "Slow", Speed: 5},
+	{Name: "Normal", Speed: 7},
+	{Name: "Fast", Speed: 10},
+	{Name: "Insane", Speed: 15},
+}
+
+const DefaultSpeed = 7
+
 func (sg *SnakeGame) IsFinished() bool {
 	return sg.Status == StatusFinished
 }
@@ -121,9 +137,11 @@ type GridPreset struct {
 }
 
 var GridPresets = []GridPreset{
+	{Name: "Tiny", Width: 15, Height: 15},
 	{Name: "Small", Width: 20, Height: 20},
 	{Name: "Medium", Width: 30, Height: 20},
 	{Name: "Large", Width: 40, Height: 20},
+	{Name: "XL", Width: 50, Height: 30},
 }
 
 // snapshot returns a shallow copy of the game safe for reading outside the lock.

ui/lobby.go

@@ -21,6 +21,8 @@ type LobbyProps struct {
 	SnakeSoloClicks     []h.H
 	SnakeMultiClicks    []h.H
 	ActiveSnakeGames    []*snake.SnakeGame
+	SelectedSpeedIndex  int
+	SpeedSelectClicks   []h.H
 }
 
 func LobbyView(p LobbyProps) h.H {
@@ -41,7 +43,7 @@ func LobbyView(p LobbyProps) h.H {
 
 	var tabContent h.H
 	if p.ActiveTab == "snake" {
-		tabContent = SnakeLobbyTab(p.SnakeNicknameBind, p.SnakeSoloClicks, p.SnakeMultiClicks, p.ActiveSnakeGames)
+		tabContent = SnakeLobbyTab(p.SnakeNicknameBind, p.SnakeSoloClicks, p.SnakeMultiClicks, p.ActiveSnakeGames, p.SelectedSpeedIndex, p.SpeedSelectClicks)
 	} else {
 		tabContent = connect4LobbyContent(p)
 	}

ui/snakeboard.go

@@ -45,10 +45,7 @@ func SnakeBoard(sg *snake.SnakeGame) h.H {
 	}
 
 	// Cell size scales with grid dimensions
-	cellSize := 20
+	cellSize := cellSizeForGrid(state.Width, state.Height)
-	if state.Width <= 20 {
-		cellSize = 24
-	}
 
 	var rows []h.H
 	for y := 0; y < state.Height; y++ {
@@ -94,3 +91,22 @@ func SnakeBoard(sg *snake.SnakeGame) h.H {
 	attrs = append(attrs, rows...)
 	return h.Div(attrs...)
 }
+
+func cellSizeForGrid(width, height int) int {
+	maxDim := width
+	if height > maxDim {
+		maxDim = height
+	}
+	switch {
+	case maxDim <= 15:
+		return 28
+	case maxDim <= 20:
+		return 24
+	case maxDim <= 30:
+		return 20
+	case maxDim <= 40:
+		return 16
+	default:
+		return 14
+	}
+}

ui/snakelobby.go

@@ -7,7 +7,7 @@ import (
 	"github.com/ryanhamamura/via/h"
 )
 
-func SnakeLobbyTab(nicknameBind h.H, soloClicks, multiClicks []h.H, activeGames []*snake.SnakeGame) h.H {
+func SnakeLobbyTab(nicknameBind h.H, soloClicks, multiClicks []h.H, activeGames []*snake.SnakeGame, selectedSpeedIndex int, speedSelectClicks []h.H) h.H {
 	// Solo play buttons
 	var soloButtons []h.H
 	for i, preset := range snake.GridPresets {
@@ -56,6 +56,29 @@ func SnakeLobbyTab(nicknameBind h.H, soloClicks, multiClicks []h.H, activeGames
 		),
 	)
 
+	// Speed selector
+	var speedButtons []h.H
+	for i, preset := range snake.SpeedPresets {
+		btnClass := "btn btn-sm"
+		if i == selectedSpeedIndex {
+			btnClass += " btn-active"
+		}
+		var click h.H
+		if i < len(speedSelectClicks) {
+			click = speedSelectClicks[i]
+		}
+		speedButtons = append(speedButtons, h.Button(
+			h.Class(btnClass),
+			h.Type("button"),
+			h.Text(preset.Name),
+			click,
+		))
+	}
+	speedSelector := h.Div(h.Class("mb-4"),
+		h.Label(h.Class("label"), h.Text("Speed")),
+		h.Div(append([]h.H{h.Class("btn-group")}, speedButtons...)...),
+	)
+
 	soloSection := h.Div(h.Class("mb-6"),
 		h.H3(h.Class("text-lg font-bold mb-2"), h.Text("Play Solo")),
 		h.Div(append([]h.H{h.Class("flex gap-2 justify-center")}, soloButtons...)...),
@@ -93,6 +116,7 @@ func SnakeLobbyTab(nicknameBind h.H, soloClicks, multiClicks []h.H, activeGames
 
 	return h.Div(
 		nicknameField,
+		speedSelector,
 		soloSection,
 		multiSection,
 		gameListEl,