Level 15. Coolie Mines (2)

Locate the crack to the right of where you found the blue key; it will explode on its own as you approach. Enter the lava crack.

In the corridor following the runaway drill, destroy a crack to reveal some items.

Find a crack in the ground that slightly rises. Enter the small chamber where lava flows to uncover a cookie.

In an area with crates and a control station before a drill, destroy the crack behind the drill. Enter and navigate around to a locked chamber to find a Rail Gun.

After being propelled upwards by a fan, attempt to enter the next fan's opening. Destroy the fan from behind to exit.