press buttons to spawn units or upgrade your income. for mobile don't buy the 110$ unit because you have to control it with WASD and space . also try beating hard mode I don't think its possible. full screen highly recommended updated it so you can get more units! ok if you read down here I'll tall you that on easy mode buy the deck hand ( 5$ unit ) as soon as possible and that you should use the parrot when you are swarmed