refactoring to systems complete. also added observers for collision checks

game/game.go

@@ -3,6 +3,7 @@ package game
 import (
 	"fmt"
 	"image"
+	"openquell/observers"
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/mlange-42/arche/ecs"
@@ -28,6 +29,9 @@ func NewGame(width, height, startlevel int, startscene int) *Game {
 		Scenes:       map[int]Scene{},
 	}
 
+	observers.NewPlayerObserver(&world)
+	observers.NewParticleObserver(&world)
+
 	game.Scenes[Play] = NewLevelScene(game, startlevel)
 
 	fmt.Println(game.World.Stats().String())