Springload This trick was found by TheChickenleg, and is exclusive to world 4. The conditions to trigger this glitch are not completely understood. It is triggered when Tim is bouncing from within a goomba and is moving left so the goomba is still alive on the next frame. In these conditions, when rewinding and pausing at the bounce frame, Tim will accumulate negative horizontal velocity (toward left). Releasing the pause will send Tim leftward with a very loud bounce sound. A very high velocity can get Tim to clip inside walls, but gaining that much velocity is not always worth. For exemple, it is possible to clip inside the 4-4 puzzle piece, but it takes several minutes of gaining velocity.