Well done, I really like the character and the environments. I think a little more animation could go a long way, like for jump/death and the lava but it still looks good already. The movement felt good, the jump was precise and not too fast or floaty. I think my main criticism would be level design, death pits and spikes are both introduced at the same, so you dont really have time to get a feel for the platforming before requiring a precise jump. Also the ceilings were lower than the max jump height so some of those challenges felt a bit clunky because they interrupt your jump path (especially the part where theres a platform over lava with the rocks falling). Another benefit to adding a death animation would be that it gives the player a moment to see how and where they died and learn better from their mistakes. Overall I think this is a great start and has alotta potential.