mobile: Remove an alias Game

Fixes #1126

mobile/impl_mobile.go

@@ -17,9 +17,10 @@
 package mobile
 
 import (
+	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/mobile/ebitenmobileview"
 )
 
-func setGame(game Game) {
+func setGame(game ebiten.Game) {
 	ebitenmobileview.SetGame(game)
 }

mobile/impl_notmobile.go

@@ -17,6 +17,10 @@
 
 package mobile
 
-func setGame(game Game) {
+import (
+	"github.com/hajimehoshi/ebiten/v2"
+)
+
+func setGame(game ebiten.Game) {
 	panic("mobile: setGame is not implemented in this environment")
 }

mobile/mobile.go

@@ -23,14 +23,11 @@ import (
 	"github.com/hajimehoshi/ebiten/v2"
 )
 
-// Game defines necessary functions for a mobile game.
-type Game = ebiten.Game
-
 // SetGame sets a mobile game.
 //
 // SetGame is expected to be called only once.
 //
 // SetGame can be called anytime. Until SetGame is called, the game does not start.
-func SetGame(game Game) {
+func SetGame(game ebiten.Game) {
 	setGame(game)
 }