Double click the flag. Use the up and down arrow keys to navigate the main menu. Use the space bar to choose which mode. In story mode, use the arrow keys to move. When you get the shuriken, press space to use it. In two-player mode, use the arrow keys to control player 1. The down arrow key is to swing the sword. M is throwing shuriken. W, A, S, D is to control player 2. Use S to swing the sword. Use R to throw shuriken.
Thanks to @s9250796 (my brother) for art and level design, and a bunch of other things! HE WAS GREAT! (He's also my brother, go follow him)
