Use the ARROW KEYS to move around. SPACE toggles "visible trails" mode, which lags the game in exchange for a cool effect. You start with 10 lives, indicated by the rectangles below the player score in the top-left. A life is lost each time you collide with an enemy ship. You fire automatically every other move. The power-up allows you to fire every single move for a limited time, indicated my the timer at the top.
I've returned to Scratch after like two years to make more stuff! - Sounds made in CFXR: http://thirdcog.eu/apps/cfxr - Maybe I'll add an 8-bit "Dream is Collapsing" mix I'm working on ***EW SOMETHING WEIRD HAPPENED TO TRAILS MODE--DO NOT RECOMMEND