Very nice demo, tons of nice secrets. Loving the DMC-style combat. My only major gripe is the Jetpack functionality. I found that it actually hampered by aerial maneuverability during the Angel fight because I would unintentionally activate it while jumping, which would leave me open for a world of hurt in the middle of my jump arc. I think it might work better mapped to a different button than Up (maybe L1/LB?)
Anyways, great work!