diff --git a/main.go b/main.go
index 0847d11..29c4a6e 100644
--- a/main.go
+++ b/main.go
@@ -34,6 +34,12 @@ type building struct {
     animate animationFunc
 }
 
+type healthBar struct {
+    life int
+    damageTaken int
+    lastUpdate float64
+}
+
 func draw_plane() {
     rl.DrawPlane(
         rl.NewVector3(16, 0.0, 16), 
@@ -42,6 +48,44 @@ func draw_plane() {
     )
 }
 
+func (hb *healthBar) update(buildings []*building) {
+    const margin = 20
+    buildingsLife := 0
+    maxCityLife := 3 * len(buildings)
+    for _, b := range buildings {
+        buildingsLife += b.life
+    }
+    position := rl.NewVector2(margin, 10)
+    cityLife := (WIDTH-margin*2) * buildingsLife/maxCityLife
+
+    size := rl.NewVector2(float32(cityLife), 10)
+
+    hb.damageTaken += cityLife - hb.life
+
+    damageTaken := size
+    damageTaken.X += float32(hb.damageTaken)
+
+    rl.DrawRectangleV(position, damageTaken, rl.Orange)
+    rl.DrawRectangleV(position, size, rl.Red)
+
+    hb.lastUpdate = rl.GetTime()
+}
+
+func newHealthBar(buildings []*building) *healthBar {
+    return &healthBar{
+        life: 3 * len(buildings),
+    }
+}
+
+func (b *building) causeDamage() {
+    if b.animate != nil {
+        return
+    }
+    b.animate = shakeBuilding(*b)
+    b.life -= 1
+    fmt.Println("damage:", b.life)
+}
+
 func newBuilding(x, z float32) *building {
     color := rl.NewColor(
         uint8(rl.GetRandomValue(0, 180)),
@@ -69,7 +113,7 @@ func newBuilding(x, z float32) *building {
 
     return &building{
         color: color,
-        life: 100,
+        life: 3,
         pos: pos,
         size: size,
         boundingBox: rl.NewBoundingBox(min, max),
@@ -102,7 +146,7 @@ func shakeBuilding(b building) animationFunc {
             building.color = rl.RayWhite
         }
 
-        drawWireframe(building)
+        drawWireframe(b)
 
         shake := rl.NewVector3(
             rand.Float32() * .2 - .1,
@@ -122,15 +166,10 @@ func shakeBuilding(b building) animationFunc {
 }
 
 
-func draw_buildings(buildings []*building, selected *building) {
+func draw_buildings(buildings []*building) {
     for _, building := range buildings {
 
         hasAnimation := building.animate != nil
-        hit := building == selected && !hasAnimation 
-
-        if !hit {
-            building.animate = shakeBuilding(*building)
-        }
 
         if hasAnimation {
 
@@ -143,26 +182,33 @@ func draw_buildings(buildings []*building, selected *building) {
             continue
         }
 
+        if building.life == 0 {
+            continue
+        }
+
         drawWireframe(*building)
         rl.DrawCubeV(building.pos, building.size, building.color)
     }
 }
 
-func demage_building(camera rl.Camera, buildings []*building) *building {
-    if !rl.IsMouseButtonPressed(rl.MouseLeftButton) {
-        return nil
+func damage_building(camera rl.Camera, buildings []*building) {
+    if !rl.IsMouseButtonDown(rl.MouseLeftButton) {
+        return
     }
     ray := rl.Ray{
         Position: camera.Position,
         Direction: rl.Vector3Subtract(camera.Target, camera.Position),
     }
 
-    // var collision rl.RayCollision
     closestDistance := math.Inf(1)
     var closest *building
 
     for _, building := range buildings {
 
+        if building.life == 0 {
+            continue
+        }
+
         playerDistance := rl.Vector3Distance(camera.Position, building.pos)
 
         if playerDistance < float32(closestDistance) {
@@ -176,7 +222,10 @@ func demage_building(camera rl.Camera, buildings []*building) *building {
             }
         }
     }
-    return closest
+
+    if closest != nil {
+        closest.causeDamage()
+    }
 }
 
 func main() {
@@ -214,6 +263,7 @@ func main() {
         }
     }
 
+    healthBar := newHealthBar(buildings)
 
 	for !rl.WindowShouldClose() {
 
@@ -232,11 +282,11 @@ func main() {
 		rl.BeginMode3D(camera) 
         {
 
-            selected := demage_building(camera, buildings)
+            damage_building(camera, buildings)
 
             draw_plane()
 
-            draw_buildings(buildings, selected)
+            draw_buildings(buildings)
 
 
         } 
@@ -253,8 +303,9 @@ func main() {
             rl.Red,
         )
 
-        rl.DrawFPS(10, 10)
+        rl.DrawFPS(0, HEIGHT-30)
 
+        healthBar.update(buildings)
 
 		rl.EndDrawing()
 	}