Thank you for taking the time to play the game!
I sincerely apologize for missing the AI disclosure on the game assets. I have already paid artists to start on a full set of new sprites (I was doing it anyway) and I'll get those verified-human-drawn sprites in ASAP. I feel really bad about this and I'm upset at Itch for making it hard to spot.
Invisible walls are certainly a bug! I just checked the web build and it does seem to have this problem. That's embarrassing.
The G key for "god mode" is for testing. :-)
The game freezes between levels because it's blocking on the level generator, and the level generator can fail in rare cases. Just the reality of scrambling for a game jam, to be honest.
Thanks again for the bug reports. I know the game is really rough right now. I'll release a post-jam build in the next couple of days.