There are some things to fix
The game itself is decent and simple to play, but it's riddled with bugs that should be fixed.
For example, when you die once, you repeatedly die like 3 more times until you run out of lives. Unless those three explosions count as 1 death then disregard that.
TEACH MEGAMAN TO SHOOT UP! The bosses are too high to hit and since the player cant aim vertically they're immune to our attack. Sure weapon upgrades and everything but that shouldn't make some bosses impossible without them.
Make megaman jump higher, it'd make it a lot easier for us to land on the platforms and not fall do our deaths.
That's about it so far. Make those improvements and then resubmit.