I'm trying to beat this boss named Red Blaster, but apparently i need grenades to beat him. Thing is, i dont have any grenades. So i tried to get back out of the building to go back and get some from the first building, but as far as i can tell there's no way back out. The way you get in is on the conveyor belt, and it starts you in a room full crates and there's no door back out. I tried using the front door, but i dont have the right key card to open it. I've been wandering around for like 2 hours and can't any other exits. Somebody please tell me I'm missing something because I really dont want to start all the way over.