Well,
it was nice...
but you can beat the whole game without buying it. As soon if you have the bigger laser before the "end" of the demo go back to the left and shoot the blocks there follow this path and you wont get a end of demo screen. So good luck beating the game
Also theres a safespot at the second boss...
It was fun. But pls @Ben James if you want to make this only a demo. Just put the end of demo screen after the first laser upgrade.