Armor upgrade in Sting Chameleon stage:
Before you enter the tunnel with the falling rocks, climb up the wall above it. There will be a green machine there. Fight it. Note: Its weak point is the head. When you defeat it, a capsule will appear from the ground. The armor upgrade will be inside. Note: This will also stop the falling rocks in the tunnel.

Cheat mode:
Type xstuff during game play for all X armor, all abilities (Cutter man's scissor throw, etc.) at maximum, all four Energy Tanks filled, full health capacity, and all Bosses completed except for the last three inside the Main Fortress.

Defeating Armored Armadillo:
Shoot the Armored Armadillo with your electric spark gun when he is vulnerable. It will electrocute him, all his armor will fall off, and he will be much easier to kill.

Defeating Flame Mammoth:
Get the Boomerang Cutter and go to Flame Mammoth's stage. When you reach him, use the Bommerang Cutter on him. After a few hits, his trunk will fall off, and he will not be able to shoot out oil or change the conveyor belt's direction.

Defeating Launch Octopus:
To get rid of Launch Octopus's Piranha "homing missiles", use the Boomerang Cutter a few times to cut off his arms.