Instant fun to play, i like the stats customization where you can experiment a bit each time, the spritework is very good, i like how well these are animated for such small sprites, considering the gameplay it makes sense but i really dig that NES style tune you got, it feels like something straight out of classic megaman ^^ i also like the fact that enemies are staggered by shots and that you can cancel out each other's projectiles.
Only negative things i'd say are, the sections where you have to climb up the laser zones (like the one on the entry's screenshot for example) are a bit tedious since sometimes some of the blocks are a bit close with not that much headroom to jump, and also the laser pits where if you mess up you're done you can only restart. The last tiny issue, the character seems to have his animation freak out a bit when you run close to a wall.
Other than that, it's pretty good and super fun.
So congrats you did great there :)