My experience play by play with the game:
- Oh cool, it looks like Metroid Zero Mission, this looks competent.
- *Jumps* Oh, OK, the physics are Ghosts 'n' Goblins style where you can't change course mid-air. That's more realistic I guess, but it makes these jumps harder.
- *Grabs power-up* Oh, neat, I can fly and shoot now, this is a really neat and cool power-up, I like this. *Dies by flying into beam grid*
- So then I decide to go left at the start and wind up flying straight up into the void. Hmm, maybe I flew too high. *Lands inside the wall* Well, I guess true to Metroid, this has secret worlds.
- After falling in the water, I go right at the start now. I collect a different power-up now, one that makes you invincible and/or invisible. I proceed to get stuck between some pillars for a bit but make it out and head back left.
- Before finding a use for the invisibility power-up, I find one gives you the ability to shoot. I run to the right firing liberally and then I Won?
Anyway, it looks great, and has a lot of mechanics, enemies, power-ups and everything, but the level design definitely needs a bit of work.