Enter the Konami Code on the title screen

Clear Stage 1: Jungle

Clear Stage 2: Base #1

Clear Stage 3: Waterfall

Clear Stage 4: Base #2

Clear Stage 5: Snow Field

Clear Stage 6: Energy Zone

Clear Stage 7: Hangar

Clear Stage 8: Alien's Lair and beat the game

Destroy every turret in Stage 2

Move around and avoid the Stage 6 boss without shooting

Defeat the Stage 2 boss without destroying any projectiles or turrets, and without using the Konami Code

Destroy every turret in Stage 4

Beat the game's second loop

Defeat the Stage 1 boss using the Laser without jumping or shooting diagonally

Beat the game without crouching - only allowed in Stage 6 to drop through the platforms

Reach the boss in Stage 1 without shooting or dying

Reach the boss in Stage 3 without shooting or dying, and without using the Konami Code

Kill 10 Gunners in Stage 6 without damaging any other enemies and without using the Konami Code

Defeat the Stage 3 boss without damaging its arms or jumping, and without using the Konami Code

Defeat the Stage 4 boss without destroying any of its projectiles or its turret

Let the Stage 5 boss teleport 7 times without destroying any of its projectiles

Defeat the Stage 7 boss while staying on the left edge of the screen and not destroying its mortars

Defeat the Stage 8 miniboss without shooting diagonally

Beat the game without collecting any weapon powerups and without using the Konami Code

Beat the game without using the Konami Code

Beat the game without dying more than twice and without using the Konami Code

Defeat the Stage 2 boss without damaging any turrets and without using the Konami Code

Reach the boss in Stage 6 without shooting and without using the Konami Code

Beat Stage 1 without pressing left and without using the Konami Code

Enter and clear Stage 4 using only the Flame

Crouch on top of one of the spiked walls in Stage 7

Reach the Stage 3 boss without pressing up or down, and without using the Konami Code

Collect every item in Stage 5 without dying

Enter and clear Stage 7 using only the Laser

Defeat the final boss without damaging the aliens or their spawners

Get zapped by the barrier in Stages 2 or 4

Score 750,000 points without using the Konami Code

Beat the default high score of 20,000 points without using the Konami Code

Clear Stage 1 without falling into the water