Not bad, but could be better. A potential idea for future levels is a max charge. If you step on a charge pad that would put you over max charge, it only takes as much as it can hold. For example, if you step on a 5 pad, and could only hold 2 more, it would only take 2, leaving 3 for future use. This could help create the need for efficient solutions, instead of just barely giving enough to make it to the next charge pad.