diff --git a/README.md b/README.md
index 7a5ec8d..cd11afd 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,3 @@
-# nilpotent-manila
+# bullet-hell
 
-> A new Smaug project
-
----
+> A DragonRuby sample
diff --git a/Smaug.toml b/Smaug.toml
index 67d753a..f582038 100644
--- a/Smaug.toml
+++ b/Smaug.toml
@@ -1,8 +1,8 @@
 [project]
 # The name of your game's executable. This should only contain a-z, A-Z, 0-9, _ or -.
-name = "nilpotent_manila"
+name = "bullet-hell"
 # The game's title. This will show up in the tile bar of your executable.
-title = "Nilpotent-Manila"
+title = "Bullet Hell"
 version = "0.1.0"
 authors = ["TODO: ldk <todo@example.com>"]
 icon = "metadata/icon.png"
diff --git a/app/main.rb b/app/main.rb
index 5bf8c57..aac6de7 100644
--- a/app/main.rb
+++ b/app/main.rb
@@ -1,7 +1,189 @@
-require 'smaug.rb'
-
 def tick args
-  args.outputs.labels  << [640, 500, 'Nilpotent-Manila', 5, 1]
-  args.outputs.labels  << [640, 460, 'A new Smaug project', 5, 1]
-  args.outputs.sprites << [576, 280, 128, 101, 'dragonruby.png']
+  args.state.base_columns   ||= 10.times.map { |n| 50 * n + 1280 / 2 - 5 * 50 + 5 }
+  args.state.base_rows      ||= 5.times.map { |n| 50 * n + 720 - 5 * 50 }
+  args.state.offset_columns = 10.times.map { |n| (n - 4.5) * Math.sin(Kernel.tick_count.to_radians) * 12 }
+  args.state.offset_rows    = 5.map { 0 }
+  args.state.columns        = 10.times.map { |i| args.state.base_columns[i] + args.state.offset_columns[i] }
+  args.state.rows           = 5.times.map { |i| args.state.base_rows[i] + args.state.offset_rows[i] }
+  args.state.explosions     ||= []
+  args.state.enemies        ||= []
+  args.state.score          ||= 0
+  args.state.wave           ||= 0
+  if args.state.enemies.empty?
+    args.state.wave      += 1
+    args.state.wave_root = Math.sqrt(args.state.wave)
+    args.state.enemies   = make_enemies
+  end
+  args.state.player         ||= {x: 620, y: 80, w: 40, h: 40, path: 'sprites/circle-gray.png', angle: 90, cooldown: 0, alive: true}
+  args.state.enemy_bullets  ||= []
+  args.state.player_bullets ||= []
+  args.state.lives          ||= 3
+  args.state.missed_shots   ||= 0
+  args.state.fired_shots    ||= 0
+
+  update_explosions args
+  update_enemy_positions args
+
+  if args.inputs.left && args.state.player[:x] > (300 + 5)
+    args.state.player[:x] -= 5
+  end
+  if args.inputs.right && args.state.player[:x] < (1280 - args.state.player[:w] - 300 - 5)
+    args.state.player[:x] += 5
+  end
+
+  args.state.enemy_bullets.each do |bullet|
+    bullet[:x] += bullet[:dx]
+    bullet[:y] += bullet[:dy]
+  end
+  args.state.player_bullets.each do |bullet|
+    bullet[:x] += bullet[:dx]
+    bullet[:y] += bullet[:dy]
+  end
+
+  args.state.enemy_bullets  = args.state.enemy_bullets.find_all { |bullet| bullet[:y].between?(-16, 736) }
+  args.state.player_bullets = args.state.player_bullets.find_all do |bullet|
+    if bullet[:y].between?(-16, 736)
+      true
+    else
+      args.state.missed_shots += 1
+      false
+    end
+  end
+
+  args.state.enemies = args.state.enemies.reject do |enemy|
+    if args.state.player[:alive] && 1500 > (args.state.player[:x] - enemy[:x]) ** 2 + (args.state.player[:y] - enemy[:y]) ** 2
+      args.state.explosions << {x: enemy[:x] + 4, y: enemy[:y] + 4, w: 32, h: 32, path: 'sprites/explosion-0.png', age: 0}
+      args.state.explosions << {x: args.state.player[:x] + 4, y: args.state.player[:y] + 4, w: 32, h: 32, path: 'sprites/explosion-0.png', age: 0}
+      args.state.player[:alive] = false
+      true
+    else
+      false
+    end
+  end
+  args.state.enemy_bullets.each do |bullet|
+    if args.state.player[:alive] && 400 > (args.state.player[:x] - bullet[:x] + 12) ** 2 + (args.state.player[:y] - bullet[:y] + 12) ** 2
+      args.state.explosions << {x: args.state.player[:x] + 4, y: args.state.player[:y] + 4, w: 32, h: 32, path: 'sprites/explosion-0.png', age: 0}
+      args.state.player[:alive] = false
+      bullet[:despawn]          = true
+    end
+  end
+  args.state.enemies = args.state.enemies.reject do |enemy|
+    args.state.player_bullets.any? do |bullet|
+      if 400 > (enemy[:x] - bullet[:x] + 12) ** 2 + (enemy[:y] - bullet[:y] + 12) ** 2
+        args.state.explosions << {x: enemy[:x] + 4, y: enemy[:y] + 4, w: 32, h: 32, path: 'sprites/explosion-0.png', age: 0}
+        bullet[:despawn] = true
+        args.state.score += 1000 * args.state.wave
+        true
+      else
+        false
+      end
+    end
+  end
+
+  args.state.player_bullets = args.state.player_bullets.reject { |bullet| bullet[:despawn] }
+  args.state.enemy_bullets  = args.state.enemy_bullets.reject { |bullet| bullet[:despawn] }
+
+  args.state.player[:cooldown] -= 1
+  if args.inputs.keyboard.key_held.space && args.state.player[:cooldown] <= 0 && args.state.player[:alive]
+    args.state.player_bullets << {x: args.state.player[:x] + 12, y: args.state.player[:y] + 28, w: 16, h: 16, path: 'sprites/star.png', dx: 0, dy: 8}.sprite
+    args.state.fired_shots       += 1
+    args.state.player[:cooldown] = 10 + 20 / args.state.wave
+  end
+  args.state.enemies.each do |enemy|
+    if Math.rand < 0.0005 + 0.0005 * args.state.wave && args.state.player[:alive] && enemy[:move_state] == :normal
+      args.state.enemy_bullets << {x: enemy[:x] + 12, y: enemy[:y] - 8, w: 16, h: 16, path: 'sprites/star.png', dx: 0, dy: -3 - args.state.wave_root}.sprite
+    end
+  end
+
+  args.outputs.background_color = [0, 0, 0]
+  args.outputs.primitives << args.state.enemies.map do |enemy|
+    [enemy[:x], enemy[:y], 40, 40, enemy[:path], -90].sprite
+  end
+  args.outputs.primitives << args.state.player if args.state.player[:alive]
+  args.outputs.primitives << args.state.explosions
+  args.outputs.primitives << args.state.player_bullets
+  args.outputs.primitives << args.state.enemy_bullets
+  accuracy = args.state.fired_shots.zero? ? 1 : (args.state.fired_shots - args.state.missed_shots) / args.state.fired_shots
+  args.outputs.primitives << [
+    [0, 0, 300, 720, 96, 0, 0].solid,
+    [1280 - 300, 0, 300, 720, 96, 0, 0].solid,
+    [1280 - 290, 60, "Wave     #{args.state.wave}", 255, 255, 255].label,
+    [1280 - 290, 40, "Accuracy #{(accuracy * 100).floor}%", 255, 255, 255].label,
+    [1280 - 290, 20, "Score    #{(args.state.score * accuracy).floor}", 255, 255, 255].label,
+  ]
+  args.outputs.primitives << args.state.lives.times.map do |n|
+    [1280 - 290 + 50 * n, 80, 40, 40, 'sprites/circle-gray.png', 90].sprite
+  end
+  #args.outputs.debug << args.gtk.framerate_diagnostics_primitives
+
+  if (!args.state.player[:alive]) && args.state.enemy_bullets.empty? && args.state.explosions.empty? && args.state.enemies.all? { |enemy| enemy[:move_state] == :normal }
+    args.state.player[:alive] = true
+    args.state.player[:x]     = 624
+    args.state.player[:y]     = 80
+    args.state.lives          -= 1
+    if args.state.lives == -1
+      args.state.clear!
+    end
+  end
+end
+
+def make_enemies
+  enemies = []
+  enemies += 10.times.map { |n| {x: Math.rand * 1280 * 2 - 640, y: Math.rand * 720 * 2 + 720, row: 0, col: n, path: 'sprites/circle-orange.png', move_state: :retreat} }
+  enemies += 10.times.map { |n| {x: Math.rand * 1280 * 2 - 640, y: Math.rand * 720 * 2 + 720, row: 1, col: n, path: 'sprites/circle-orange.png', move_state: :retreat} }
+  enemies += 8.times.map { |n| {x: Math.rand * 1280 * 2 - 640, y: Math.rand * 720 * 2 + 720, row: 2, col: n + 1, path: 'sprites/circle-blue.png', move_state: :retreat} }
+  enemies += 8.times.map { |n| {x: Math.rand * 1280 * 2 - 640, y: Math.rand * 720 * 2 + 720, row: 3, col: n + 1, path: 'sprites/circle-blue.png', move_state: :retreat} }
+  enemies += 4.times.map { |n| {x: Math.rand * 1280 * 2 - 640, y: Math.rand * 720 * 2 + 720, row: 4, col: n + 3, path: 'sprites/circle-green.png', move_state: :retreat} }
+  enemies
+end
+
+def update_explosions args
+  args.state.explosions.each do |explosion|
+    explosion[:age]  += 0.5
+    explosion[:path] = "sprites/explosion-#{explosion[:age].floor}.png"
+  end
+  args.state.explosions = args.state.explosions.reject { |explosion| explosion[:age] >= 7 }
+end
+
+def update_enemy_positions args
+  args.state.enemies.each do |enemy|
+    if enemy[:move_state] == :normal
+      enemy[:x]          = args.state.columns[enemy[:col]]
+      enemy[:y]          = args.state.rows[enemy[:row]]
+      enemy[:move_state] = :dive if Math.rand < 0.0002 + 0.00005 * args.state.wave && args.state.player[:alive]
+    elsif enemy[:move_state] == :dive
+      enemy[:target_x] ||= args.state.player[:x]
+      enemy[:target_y] ||= args.state.player[:y]
+      dx               = enemy[:target_x] - enemy[:x]
+      dy               = enemy[:target_y] - enemy[:y]
+      vel              = Math.sqrt(dx * dx + dy * dy)
+      speed_limit      = 2 + args.state.wave_root
+      if vel > speed_limit
+        dx /= vel / speed_limit
+        dy /= vel / speed_limit
+      end
+      if vel < 1 || !args.state.player[:alive]
+        enemy[:move_state] = :retreat
+      end
+      enemy[:x] += dx
+      enemy[:y] += dy
+    elsif enemy[:move_state] == :retreat
+      enemy[:target_x] = args.state.columns[enemy[:col]]
+      enemy[:target_y] = args.state.rows[enemy[:row]]
+      dx               = enemy[:target_x] - enemy[:x]
+      dy               = enemy[:target_y] - enemy[:y]
+      vel              = Math.sqrt(dx * dx + dy * dy)
+      speed_limit      = 2 + args.state.wave_root
+      if vel > speed_limit
+        dx /= vel / speed_limit
+        dy /= vel / speed_limit
+      elsif vel < 1
+        enemy[:move_state] = :normal
+        enemy[:target_x]   = nil
+        enemy[:target_y]   = nil
+      end
+      enemy[:x] += dx
+      enemy[:y] += dy
+    end
+  end
 end
diff --git a/metadata/game_metadata.txt b/metadata/game_metadata.txt
index b5fa83c..fecb681 100755
--- a/metadata/game_metadata.txt
+++ b/metadata/game_metadata.txt
@@ -2,9 +2,9 @@
 # Do not manually edit this file. Edit Smaug.toml instead.
 
 devid=todo-change-me
-devtitle=TODO: ${REPO_OWNER} &lt;todo@example.com&gt;
-gameid=${REPO_NAME_SNAKE}
-gametitle=${REPO_NAME_TITLE}
+devtitle=TODO: ldk &lt;todo@example.com&gt;
+gameid=nilpotent_manila
+gametitle=Nilpotent-Manila
 version=0.1.0
 icon=metadata/icon.png
 compile_ruby=false
diff --git a/sprites/circle-blue.png b/sprites/circle-blue.png
new file mode 100644
index 0000000..1726d2a
Binary files /dev/null and b/sprites/circle-blue.png differ
diff --git a/sprites/circle-gray.png b/sprites/circle-gray.png
new file mode 100644
index 0000000..960f191
Binary files /dev/null and b/sprites/circle-gray.png differ
diff --git a/sprites/circle-green.png b/sprites/circle-green.png
new file mode 100644
index 0000000..43cf7ee
Binary files /dev/null and b/sprites/circle-green.png differ
diff --git a/sprites/circle-orange.png b/sprites/circle-orange.png
new file mode 100644
index 0000000..5604a42
Binary files /dev/null and b/sprites/circle-orange.png differ
diff --git a/sprites/misc/explosion-0.png b/sprites/explosion-0.png
similarity index 100%
rename from sprites/misc/explosion-0.png
rename to sprites/explosion-0.png
diff --git a/sprites/misc/explosion-1.png b/sprites/explosion-1.png
similarity index 100%
rename from sprites/misc/explosion-1.png
rename to sprites/explosion-1.png
diff --git a/sprites/misc/explosion-2.png b/sprites/explosion-2.png
similarity index 100%
rename from sprites/misc/explosion-2.png
rename to sprites/explosion-2.png
diff --git a/sprites/misc/explosion-3.png b/sprites/explosion-3.png
similarity index 100%
rename from sprites/misc/explosion-3.png
rename to sprites/explosion-3.png
diff --git a/sprites/misc/explosion-4.png b/sprites/explosion-4.png
similarity index 100%
rename from sprites/misc/explosion-4.png
rename to sprites/explosion-4.png
diff --git a/sprites/misc/explosion-5.png b/sprites/explosion-5.png
similarity index 100%
rename from sprites/misc/explosion-5.png
rename to sprites/explosion-5.png
diff --git a/sprites/misc/explosion-6.png b/sprites/explosion-6.png
similarity index 100%
rename from sprites/misc/explosion-6.png
rename to sprites/explosion-6.png
diff --git a/sprites/misc/dragon-0.png b/sprites/misc/dragon-0.png
deleted file mode 100644
index fb179af..0000000
Binary files a/sprites/misc/dragon-0.png and /dev/null differ
diff --git a/sprites/misc/dragon-1.png b/sprites/misc/dragon-1.png
deleted file mode 100644
index 8cfe531..0000000
Binary files a/sprites/misc/dragon-1.png and /dev/null differ
diff --git a/sprites/misc/dragon-2.png b/sprites/misc/dragon-2.png
deleted file mode 100644
index cb462e1..0000000
Binary files a/sprites/misc/dragon-2.png and /dev/null differ
diff --git a/sprites/misc/dragon-3.png b/sprites/misc/dragon-3.png
deleted file mode 100644
index 04c4977..0000000
Binary files a/sprites/misc/dragon-3.png and /dev/null differ
diff --git a/sprites/misc/dragon-4.png b/sprites/misc/dragon-4.png
deleted file mode 100644
index b29fa3d..0000000
Binary files a/sprites/misc/dragon-4.png and /dev/null differ
diff --git a/sprites/misc/dragon-5.png b/sprites/misc/dragon-5.png
deleted file mode 100644
index 99f4e74..0000000
Binary files a/sprites/misc/dragon-5.png and /dev/null differ
diff --git a/sprites/misc/explosion-sheet.png b/sprites/misc/explosion-sheet.png
deleted file mode 100644
index 8559a5c..0000000
Binary files a/sprites/misc/explosion-sheet.png and /dev/null differ
diff --git a/sprites/star.png b/sprites/star.png
new file mode 100644
index 0000000..e0ee0f9
Binary files /dev/null and b/sprites/star.png differ