#1. Armored Armadillo Stage.It's located behind the first robot that digs trhu the wall. #2.Storm Eagle Stage. There is a rotaiting turet that rises on a tower, destroy it stand there press up, the tower will rise climb the building go over it and shoot through the window on the opposite side and there is the Sub-Tank. #3. Flame Mammoth Stage. In the area Where theres multiple levels above the lava. You need to make it to the very top left then Dash/jump to the left.there is a hole on that wall that will lead you to the Sub-Tank. #4. Spark Mandrill Stage. Make your way right and stay at the bottom, theres going to be a wall between you and the Sub-Tank you need the boomerang upgrade. Jump then shoot as you land the boomerang should drag the Sub-Tank to you.