As you already know, I think, creating looping maps for game jam is not a great idea :) I've passed that loop (double loop with that cave) twice. And was very disappointed until read comments below where found information about that first battery that is hidden in some dark room (as every room there) behind the broken window (that looks almost like an ordinary window in the dark). It's better to place the first battery at some clearly visible place to show player mechanics of the game with no frustration. Besides that I have not seen any mecha in the game. I have heard it, it's nice. That flying tablets are funny, and visuals are very nice. But I believe adding some more visible mecha stuff (mecha enemies, cockpit or some HUD indicating that you are inside mecha) in the game would make it way more enjoyable