Showdown is the basic fighting mode, similarly to Smash in Super Smash Bros. You can fight between a friend or a computer player (or a harder version of the CPU). To fight with a friend, you just select player one's character, using right click, and select player two's character using left click. Once both characters are chosen, a bar will appear, saying "READY TO FIGHT!". Pressing it, (or pressing Enter) will make you go into a stage select menu. You can pick your stage, and fight. To fight with a CPU, click where it says "P2", with the blue background. If done properly, P2 will be replaced with "CPU", and the background will be gray. After that, chose your character by pressing left click, and the CPU's by pressing right click. Then the same thing will happen if you were fighting with a friend. To fight with a Hard CPU, just press it again, after P2's box says CPU. If done correctly, the box will be gray and say "CPU!" instead of "CPU". Though, where it normally says "CPU" will be red. Do everything else the same way you would every other way.