To get Captain Olimar trapped, go to the Forest Of Hope on Day 2. Take out your Red Pikmin and have them break down the gate. Next, have Olimar run to the left and through the pond. Run off the cliff into the Nova Blaster area. You have now gotten Captain Olimar trapped. There is no way out. You can leave the Nova Blaster area through the hole in the stump, but you cannot get back to the Shock Absorber area, the Yellow Onion, the Landing Site, the Burrowing Snagrets area, or the area through the first gate. If you want to escape, bring Yellow Pikmin with you and arm them with Bomb-Rocks in the can near the Nova Blaster.