Space to select a level WASD or Arrow Keys to Move. Click/Space bar to shoot When you defeat a boss, select a card to upgrade your robot. The more lives you have when you win, the more upgrades you get, with a max of 3 per boss.
This is the thirteenth in a series on my Youtube channel, where I polish up your scratch projects, to show how simple concepts can become refined games. Credit to monkebru11 for the original project and concept.