The gameplay is really good but the level design frustrated me a little  cause the there were some one block wide vertical corridors and some blind jumps which required you to get hit.

I missed music and sound. The controls are good and mechanics too. The art is very reminiscent the GB games.

Gameplay feels amazing, props to your for implementing a tutorial, this is one of the games I had the least problem to get played. I like the minimalistic approach, convoluted art don't look too good in gameboy, some brackground art is kinda needed tho. Also some falls are too high to notice if an enemy is waiting for you :)