Great job submitting a game! I appreciate you coming back to participate every year, its always fun to play your games! I am in love with the visuals on this one. It reminds me of some old DOS games I played as a kid. My favorite room was the final waterfall screen. Neat touch to have the classic "behind the waterfall" end the game.
I died my first playthrough. I couldn't tell if there were invincibility frames but I almost immediately died to a frog who got on top of me. As others have said starting over could be frustrating for sure, but the game isn't long enough for it to bother me. It was quick to get back to where I died. The upgrades were hard to understand, a simple change in iconography could help. Maybe boots instead of the spring, and changing the bomb to the gun. You could start the player off without a gun until they get the upgrade. I did like how you incorporated the block puzzles with the switches in different rooms.
Thanks for participating and I hope to see you next year!