I like it. For the first few levels, I was thinking, "I'm so tired of 'avoid the spikes' platformers," but the solid control and competent level design kept me interested, and I enjoyed playing until the end. Also, I kind of want to thank you for for not making the ice level slippy and slidey. After 30+ years of playing games, I've decide that slippery ice levels are one of the worst platform mechanics ever.
The ending screen went by too quickly, and I think it's a cliffhanger? No Victory message, no "You Win!" It would be nice to see a little more. It also might be nice to see a more detailed background. Nothing complex, just enough to deepen the mood a bit. 8-bit music is great.