when the game loads, press the green flag again Instructions - Left and Right keys to move, Z to run, Up key to jump, Down to crouch, Space on ground to spinjump, when in air press Space to long jump, also when in air press Down to ground pound. Hold Z while touching a koopa shell to pick it up. Release Z to throw the shell. Jump and hit or Ground Pound blocks to get items.
Big shout out to @pareshvernekar