Wow! This game is amazing!
I like the retro graphics.

Yeah I like that game, although you can hack yourself through the spikes. Just move through them without jumping... The effect on entering a level could be a little faster though. Nevertheless I really love platformers and you did a good job!

Great entry, controls are tight and it plays smoothly.

I like it, it's really good. You can put a checkpointer later, if you're update it.

Ehhh... I didn't enjoy it. The jump is too fast and not always responsive, horizontal movement is slippery and imprecise, touching a wall keeps you from going upward which is the difference between life and death while submerged, the slow camera zoom-out effect just obscures your view so you can't see what's coming right in front of you, and the checkpoints are unforgiving. I got to the screen with the spike-box blocking an air pocket in the middle of a long passageway a few times and was too annoyed to keep playing. Died 108 times and none of those times felt like my fault.

I was kinda missing an overall goal or directive apart from just moving thorugh the levels. Also, swimming was a pain in the ass because you have to keep pressing up really fast or you sink back down.
Apart from that, it's really nice.

This game is quite challenging, but I did beat it twice, second time only like 30 deaths.

BTW if you have not yet picked out a name for the main character I recommend "Slipshoes McSwimsbad" :P