Not a bad game, but I've certainly seen better games in this style.
I think the coding is to blame here, it doesn't cover many of the possibilities of user interaction.
Also I think you skipped the testing phase during game development.
The music was alright - classic 8 bit style.
It was somewhat challenging , not too much.
You included medals, those were essential.
Now for the improvements-
The hitboxes really need to be calibrated especially with the crushing pistons.
The animation was really simple, you should make more vibrant animations.
The disappearing traps, as everyone pointed out already.
Shockingly, i clicked on the little space ship in the level select menu after completing 3 levels and it took me to the final battle.
This is an average platformer that could have been made a lot better with careful coding and testing. I hope the next version is better.
Best of luck!