Treat them like piñatas to pick up some items. Part two begins in an area with a lot of webbed bodies hanging from the ceiling. Push it into the claw thing by the door to open it. You have to push this one quite a bit, down a dark passage into a room with three Octabrains. Just melee these things, ammo is scarce in this stage. Some of the women will explode Octababies. Keep an eye out for more of these, you’ll use them to bounce around and reach new areas. Move around the ledge and bounce on the growth below to keep going.
Don’t use rockets, they’ll throw them back. You’ll fight your first Octabrain up ahead.