I would like to add to the comment of "Lindashee".

1) An explanation of the controls is necessary because in addition to the standard W/A/S/D/Spase, the game also uses Shift (to create bombs that kill enemies), which can only be learned by accident.

2) I have nothing to add.

3) The character can jump while moving, but if he is standing next to a wall, the jump does not occur.

4) The platforms on levels 3 and 4 do not have collision, which makes it impossible to complete these levels.

5) I have nothing to add.

A few things could help to improve the game, as there's potential.

1) Explaining control scheme on the page or within the game itself - I wasn't sure what to do with the main menu at first. 
2) The music seems to play in the 1st level but not the others + dying results in the music restarting on top of the last bit of music playing. At one point I had 4-5 tracks playing simultaneously
3) It looks like you can't jump while holding a direction key,  I think that might make the game tad too hard

4) Few times where I landed on the moving platforms only to die instantly cause it moved away without me
5) Perhaps add a screenshot of one of your levels on the page too !! Show people what the game is about ;)