Really good overall! great presentation and great power-scaling so long as you go down the right path (my 1st time wasn't fun :P). Loved the weapon variety, although having a cool-down or something would've made the desicion to use a weaker weapon more appealing. Also, I think it really needs a mini-map or some distincitive features whenever you reach some points. It's really hard to tell yourself where you'd gone - I ended up spinning pretty much in place for a while.
Also, wasn't a fan of the all-dark portion.... but, thanks for putting in the 45s potion <3. Managed to completed due to that. Great work!!!