Yeah I'm not sure what changes you're allowed to make after the submission period, so I'm playing it safe :)
Will certainly be fixing those bits after the jam. There's a few bugs like the "restart level" that slipped past me - well that sucks! Thanks for letting me know so I can iron them out after the jam!
I think the spikes are being caused by shaders, once they're cached they seem to work a lot better or with no issues :)