I think it's a great game for 3 days! Good job!
Some points:
I know it's a game, but I would try to extend the atmospheric entry because it makes less sense that once you've made it through the atmosphere, you'd still overheat.
I really get a sense of RNG from this and I don't know if this is the case but there could be more notable/obvious markings to make speed running it and replaying it worth the time.
I feel like for the size of this, you don't need a checkpoint. The check point felt almost like a bug to me? I also hit the checkpoint before grabbing the chute, so if there is a checkpoint, I feel it should exist on the chute acquisition.
Otherwise, this was kinda cool and fun! Felt like if Pilotwings was released on NES