Yeah difficulty is something I've kept trying to adjust. I keep making new versions of the starting level, with the current one being the easiest. I thought that one would be fine but I guess not. Not sure if I'll keep making easier ones, I'll have to think about it once I finish making the levels that are currently planned, if not I can just keep adjusting. The metallic level is gonna be changed completely, something new with a similar concept. I just kept it in there so there's another level to play after it was removed from previous demo versions.
The shrinking glitch, it's so strange. Maybe it happens on lower end computers since you said you had FPS issues on the grass level? Though I have played on my laptop before that also has low FPS on that level and it still doesn't happen there. Maybe you could tell me what specs you have and I can ask the other people it happens to, maybe there's a correlation there?
Lives aren't meant to reset until you lose them all, you can gain more by collecting the yellow Sun Crystals.
The characters each have different special moves that may help you with certain areas or give you different ways to defeat enemies. None of the levels require a specific move but it can change the way you approach things.
I do intend to change the menu buttons and maybe the camera, just haven't gotten around to it yet.
Thank you for playing my game! :)