Wow the game is so big ^^ Id love to have seen a map of it, would have been great for navigation too. Though it wouldn't help for the invisible blocks, those are super hard to find, and In general your game is just really hard! haha I guess checkpoints didn't make it in because of time? fully restarting after 30 mins is tough in any game.
Congrats on getting this much done, I'd love to play it with sound and a bit more development :)