GJ, GJ, I feel like the mechanic and level layout is working very well for a jam game. However gaining blood without hurting yourself is something that is missing in the game loop. It feels like the best way to remedy this is die yourself, but I cant imagine that is a desireable result. You could potentially take a page out of ultrakill's book where they have a main engagement tool through shooting and second one through melee that lets you replenish your mana and keep the gameplay going more organically.