diff --git a/src/constants/index.ts b/src/constants/index.ts
index ab25ba9..9112e5d 100644
--- a/src/constants/index.ts
+++ b/src/constants/index.ts
@@ -1 +1,3 @@
+export * from './scenes'
+export * from './sprites'
 export * from './tags'
diff --git a/src/types/scene.ts b/src/constants/scenes.ts
similarity index 100%
rename from src/types/scene.ts
rename to src/constants/scenes.ts
diff --git a/src/types/sprite.ts b/src/constants/sprites.ts
similarity index 100%
rename from src/types/sprite.ts
rename to src/constants/sprites.ts
diff --git a/src/gameobjects/bullet.ts b/src/gameobjects/bullet.ts
index 1e09e88..83f9800 100644
--- a/src/gameobjects/bullet.ts
+++ b/src/gameobjects/bullet.ts
@@ -1,7 +1,8 @@
 import { Tag } from '../constants'
-import type { Player } from './player'
+import type { Enemy, Player } from '../types'
 
 const BULLET_SPEED = 600
+const BULLET_DAMAGE = 20
 
 export function addBullet(player: Player) {
   const bullet = add([
@@ -15,6 +16,12 @@ export function addBullet(player: Player) {
     Tag.bullet,
   ])
 
+  bullet.onCollide(Tag.enemy, (enemy) => {
+    bullet.destroy()
+    const currentEnemy = enemy as Enemy
+    currentEnemy.hurt(BULLET_DAMAGE)
+  })
+
   return bullet
 }
 
diff --git a/src/gameobjects/enemy.ts b/src/gameobjects/enemy.ts
index c38651c..88b10b5 100644
--- a/src/gameobjects/enemy.ts
+++ b/src/gameobjects/enemy.ts
@@ -1,16 +1,32 @@
-import { Tag } from '../constants'
-import { ghosty } from '../sprites'
-import type { Player } from './player'
+import { Sprite, Tag } from '../constants'
+import type { Player } from '../types'
 
 const ENEMY_SPEED = 200
 
 export function addEnemy(x: number, y: number, player: Player) {
-  const enemy = add([ghosty, pos(x, y), anchor('center'), Tag.enemy])
+  const enemy = add([
+    sprite(Sprite.ghosty),
+    pos(x, y),
+    anchor('center'),
+    health(100),
+    opacity(1),
+    area(),
+    Tag.enemy,
+  ])
 
   enemy.onUpdate(() => {
     const dir = player.pos.sub(enemy.pos).unit()
     enemy.move(dir.scale(ENEMY_SPEED))
   })
 
+  enemy.onHurt(() => {
+    enemy.opacity = enemy.hp() / 100
+  })
+
+  enemy.onDeath(() => {
+    enemy.destroy()
+    addKaboom(enemy.pos)
+  })
+
   return enemy
 }
diff --git a/src/gameobjects/index.ts b/src/gameobjects/index.ts
index 8c85dea..6ff964a 100644
--- a/src/gameobjects/index.ts
+++ b/src/gameobjects/index.ts
@@ -1,2 +1,3 @@
+export * from './bullet'
 export * from './enemy'
 export * from './player'
diff --git a/src/gameobjects/player.ts b/src/gameobjects/player.ts
index 680b82c..c837c40 100644
--- a/src/gameobjects/player.ts
+++ b/src/gameobjects/player.ts
@@ -1,10 +1,16 @@
-import { Tag } from '../constants'
+import { Sprite, Tag } from '../constants'
 import { addCursorKeys } from '../events'
-import { bean } from '../sprites'
 import { addBullet } from './bullet'
 
 export function addPlayer(x = center().x, y = center().y) {
-  const player = add([bean, pos(x, y), rotate(0), anchor('center'), Tag.player])
+  const player = add([
+    sprite(Sprite.bean),
+    pos(x, y),
+    rotate(0),
+    anchor('center'),
+    area(),
+    Tag.player,
+  ])
 
   addCursorKeys(player)
 
@@ -14,5 +20,3 @@ export function addPlayer(x = center().x, y = center().y) {
 
   return player
 }
-
-export type Player = ReturnType<typeof addPlayer>
diff --git a/src/scenes/game.ts b/src/scenes/game.ts
index 089126b..bbc6a84 100644
--- a/src/scenes/game.ts
+++ b/src/scenes/game.ts
@@ -1,14 +1,14 @@
+import { Scene } from '../constants'
 import { addEnemy, addPlayer } from '../gameobjects'
-import { Scene } from '../types'
 
 scene(Scene.game, () => {
   const player = addPlayer()
 
   add([text('Press arrow keys', { width: width() / 2 }), pos(12, 12)])
 
-  for (let i = 0; i < 3; i++) {
+  loop(5, () => {
     const x = rand(0, width())
     const y = rand(0, height())
     addEnemy(x, y, player)
-  }
+  })
 })
diff --git a/src/scenes/index.ts b/src/scenes/index.ts
index 7cece75..bacd843 100644
--- a/src/scenes/index.ts
+++ b/src/scenes/index.ts
@@ -1,7 +1,7 @@
 import './game'
 import './preload'
 
-import { Scene } from '../types'
+import { Scene } from '../constants'
 
 export function start() {
   go(Scene.preload)
diff --git a/src/scenes/preload.ts b/src/scenes/preload.ts
index c2adfe6..83c54dc 100644
--- a/src/scenes/preload.ts
+++ b/src/scenes/preload.ts
@@ -1,8 +1,7 @@
-import { Scene, Sprite } from '../types'
+import { Scene, Sprite } from '../constants'
 
 scene(Scene.preload, () => {
   loadSprite(Sprite.bean, 'sprites/bean.png')
   loadSprite(Sprite.ghosty, 'sprites/ghosty.png')
-
   go(Scene.game)
 })
diff --git a/src/sprites/bean.ts b/src/sprites/bean.ts
deleted file mode 100644
index 65bb597..0000000
--- a/src/sprites/bean.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-import { Sprite } from '../types'
-
-export const bean = sprite(Sprite.bean)
diff --git a/src/sprites/ghosty.ts b/src/sprites/ghosty.ts
deleted file mode 100644
index 325a16e..0000000
--- a/src/sprites/ghosty.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-import { Sprite } from '../types'
-
-export const ghosty = sprite(Sprite.ghosty)
diff --git a/src/sprites/index.ts b/src/sprites/index.ts
deleted file mode 100644
index b174efe..0000000
--- a/src/sprites/index.ts
+++ /dev/null
@@ -1,2 +0,0 @@
-export * from './bean'
-export * from './ghosty'
diff --git a/src/types/gameobject.ts b/src/types/gameobject.ts
deleted file mode 100644
index 4835fb3..0000000
--- a/src/types/gameobject.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-import { addPlayer } from '../gameobjects'
-
-export type Player = ReturnType<typeof addPlayer>
diff --git a/src/types/gameobjects.ts b/src/types/gameobjects.ts
new file mode 100644
index 0000000..95e39d9
--- /dev/null
+++ b/src/types/gameobjects.ts
@@ -0,0 +1,5 @@
+import { addBullet, addEnemy, addPlayer } from '../gameobjects'
+
+export type Bullet = ReturnType<typeof addBullet>
+export type Enemy = ReturnType<typeof addEnemy>
+export type Player = ReturnType<typeof addPlayer>
diff --git a/src/types/index.ts b/src/types/index.ts
index 87eac29..b138e73 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -1,3 +1 @@
-export * from './gameobject'
-export * from './scene'
-export * from './sprite'
+export * from './gameobjects'