Great first game! The movement felt pretty nice, and I liked the sneaky trap/unfair platformer style. Some of the blocks genuinely caught me off guard, which made it fun to keep pushing through and see what would happen next.
My main feedback is that the game could use clearer feedback when the player gets damaged or dies. Sometimes it was hard to tell exactly what killed me, so a death animation, sound effect, or particle effect would help a lot. A checkpoint system or a small tutorial for the trap mechanics would also make it feel smoother. Overall though, this is a really solid first game, keep going!