I think the main thing that holds the game back are the hitboxes. The tiles are in the way and you get stuck on corners often. Also the hitbox for collecting the bomb is too small.
Sometimes the bomb just reappears in my hands even tho I wasn't even near it.
The inclusion of the gas as a one hit kill is unnecessary and frustrating. A barrier that crushes you if you get stuck on a rock would have been better I think.
The level generation is messy. In combination with the big hitboxes it leads to the movement not being fun despite it being really good on its own.
I think if there were fewer but bigger rocks that would fix the issue.
The potato zombies spawn speed is nice. It's not overwhelming yet there is no down time, at least for my skill level - great job on that.

In general I think the risk vs reward idea you were going for does not work out that well because of the level generation , the big hitboxes and the speed of the bomb. It ends up being very random how long the bomb is alive.

I like the art. It is very cohesive and nice on the eyes. The music is not bad but it doesn't strike me as awesome.

Cool idea for the gameplay and the graphics are pretty good. Great work :)

Noice