Use WASD or the Arrow Keys to move.
Press the Spacebar to fire.
Normal — The most basic enemy type.
Fast — Small in size and high in speed.
Splitter — Splits into two smaller enemies upon being destroyed.
Shooter — Attacks the player by firing projectiles.
Tank — Requires two hits to destroy; the first hit destroys the lower section, while the second hit causes it to drop a reward item.
Hearts — Restores health points; collecting a Heart while at full health (= 3) triggers a screen-clearing effect.
Bullet Packs — Replenishes extra ammunition. If your ammo count exceeds 15, the pack is automatically consumed, and the enemy's size is reduced.
Invincibility — Grants a brief period of invulnerability immediately after taking damage.