diff --git a/asteroids/main.lua b/asteroids/main.lua
index c6b02c9..de4136d 100644
--- a/asteroids/main.lua
+++ b/asteroids/main.lua
@@ -7,7 +7,6 @@ local function initGame()
         ship = {
             radius = 30,
             bullet = {
-                timerLimit = 0.5,
                 radius = 5,
                 speed = 500,
                 time = 4,
@@ -65,8 +64,6 @@ local function initState()
                 y = 0,
             }
         },
-        -- the time after which the ship can fire another bullet
-        bulletTimer = game.ship.bullet.timerLimit,
         bullets = {},
         asteroids = asteroids,
         controls = {
@@ -136,19 +133,6 @@ function love.update(dt)
         end
     end
 
-    state.bulletTimer = state.bulletTimer + dt
-    if love.keyboard.isDown('s') then
-        if state.bulletTimer >= game.ship.bullet.timerLimit then
-            state.bulletTimer = 0
-            table.insert(state.bullets, {
-                x = state.ship.x + math.cos(state.ship.angle) * game.ship.radius,
-                y = state.ship.y + math.sin(state.ship.angle) * game.ship.radius,
-                angle = state.ship.angle,
-                timeLeft = game.ship.bullet.time,
-            })
-        end
-    end
-
     for _, asteroid in ipairs(state.asteroids) do
         asteroid.x = (asteroid.x + math.cos(asteroid.angle) * game.asteroids.stages[asteroid.stage].speed * dt) %
             game.width
@@ -166,6 +150,21 @@ function love.update(dt)
     end
 end
 
+function love.gamepadpressed(joystick, button)
+    if joystick ~= state.controls.joystick then
+        return
+    end
+    if button == "b" then
+        -- debounce, perhaps
+        table.insert(state.bullets, {
+            x = state.ship.x + math.cos(state.ship.angle) * game.ship.radius,
+            y = state.ship.y + math.sin(state.ship.angle) * game.ship.radius,
+            angle = state.ship.angle,
+            timeLeft = game.ship.bullet.time,
+        })
+    end
+end
+
 function love.draw()
     for y = -1, 1 do
         for x = -1, 1 do