Playing it again, I can see you unlocked the Mag Agent easter egg and added an easter egg with MC7 Tricky but here's a few things I think you could do to improve the game.
- Improve level design so everything isnt so close together. doesnt feel very platformy when you're basically taking a hop and a skip
-Have the camera follow Hank when he goes out of bounds vertically (like jumping above the fixed screen
-Perhaps give the Agents with guns the ability to shoot and maybe give Hank some attacks to throw knives or reflect shots with a sword like MC4, this would give this otherwise basic platformer some Madness feel
-Add powerups like Mario's mushroom where you can take an extra hit or add an HP bar
-Make certain enemies like the Mag Agents take more than 1 hit to kill and actually try to hit you
-I know pixel art isnt your forte as you said but perhaps add more elements to the background art, I can deal with the character sprites because they look like what they're suppose to.