I liked the rapid gameplay and easy-to-understand introductions of new mechanics. My only suggestion would be to try and program in a little bit more leeway for the player's collisions. It often felt like I jumped past the laser wall or over a energy ball but died anyways. Making the colliders for the kill boxes smaller can help make it feel more skill based.
I also really appreciated that after two seconds the level doesn't just end instantly, but gives you one last chance to get to the end. On a couple puzzles I was able to use falling platformers to jump to the exit well past two seconds which feels fun :)
Congrats on your first game!