I do find the pacing and level design to be a bit confusing to play. The game doesn't really explain mechanics in game (either by showing or telling) and I found myself getting lost at the beginning.
Controls are alright but a little bit frustrating with the jumping due to the really small gaps you have to jump into. Perhaps bigger gaps might help it better.
I sometimes can't pick up canisters but I am unsure why (hit detection or not allowed to pick up yet?) and so having a visual indicator explain why if it isn't a bug would be better. If it is a bug I think making the collider shape for the canisters bigger might be better. I got stuck because of this :(
The character sprite for the guy you play is does look alright some tiles blend into the background a bit much. I may consider giving them a thicker outline.
I like the art for the character you play as though and the music isn't too bad. I do think it might be better to have more linear levels and have more of a challenge factor. Right now I just feel like all I am doing is running around and trying to get canisters that won't get collected :c
Nice attempt though! For your second released game its not bad. Keep practicing and you'll improve over time :D