A boss would give you another star! Maybe a rat that abducted Volty into the drain to power his evil plans instead of just "He's been lost in the sink".
I would indicate different "power reduction levels" (standing still: 1/s; moving: 2/s; jumping 5/jump etc) with some kind of animation at the "health", pardon, power bar.
Standing still at the charge station should be enough, same for the "charge" buttons. (Instead of having to press the "down" button)
The sound (jumping/walking etc.) needs some more work! The soundtrack is good!
- The overall game length is far too short, it should be at least triple or quadruple!
- The replayability of this game is not high at the moment (players will probably only finish it once): Add a level-(or scene)selector after finishing the game with monitoring of the time required for each level/scene, as well as the total time, and show us your programmers "best" time you finished the scenes and complete game in: With minimum programming effort (just some timers) you will motivate players to challenge your best time and increase replayability by 1000fold!
For further development of levels:
- Charge stations that do not fully recharge;
- Charge stations that only recharge once;
- Charge buttons that have to be filled with a certain amount of energy, Volty has to bring energy multiple times there (from different non-recharging charge stations, or the buttons not only unlock the door but add some dangers on the route for Volty when he is backtracking);
I like the green tone, but when adding later levels, think about using different colors, too ;)