This game is like tower defense, you can upgrade the stationary shooter. Except there's a twist, the zombies aren't going for the exit, they are going for the shooter, and you my friend, are the shooter. Think of this as a small remake of FRONTLINE DEFENSE in Roblox. Arrow keys or A and D to turn. Space/click/tap to shoot. The small arrow on the side is to open the upgrade menu and close it. You require the zombies neutralized bar to be at 50 to win. If the zombies get your health to 0, you lose. Stronger zombies spawn less frequently and are difficult to deal with, although they give more money.
FDL Developers on Roblox for Inspiration. My coding teacher for suggestions. And me, for making and drawing all backgrounds and sprites. (Except for the skip button, I just edited that from the scratch sprite).