Nid help on coding

im creating a game like this one: http://www.sushidejaneiro.com/issai.html
if you can make a full tutorial pls do :slight_smile: but i only nid the random code the one used for the ninjas. but i want mine to appear only by two’s. and the code that u can only press one key at a time.

and what category of game this is or what type of game this is?

thnx!!