Nice little game. The concept is good, just needs a bit more thought I think. I was able to run through the levels quickly, as long as I avoided Green and Brown squares. There wasn't much consequence for walking in fire or water or ice. I get that you can pick up a jackhammer to break brown blocks but it's not really that important as the levels were quite simple. There needs to be a cost to taking certain routes, for example you move slow in water, fire kills you instantly so if you slide off of ice into it you're dead. the Jackhammer needs to be more valuable as a tool so perhaps you should make some parts completely blocked and if you lose the hammer you need to go back to get it.
These are just a few ideas that popped into my head when playing. Great effort ! :)