Posted on 10 May 16 at 06:061. Can I collect everything, or go back to get what I missed. Meaning the unlockable characters. After doom is defetad on the same save (I've read once you leave a sub level you cannot go back) aside from that one can I?2. Ive made it to just project labs, act 1. When do I get to iron mans lab for the coop achievements? Any other info or tips would be greatly appreciated as I've put this game off for years as my gold edition got scratched and was lucky and finally able to snag it digitally on sale.