Clear the alien infestation at Stonehenge with minimal collateral damage.
The above image is the main gameplay screen. On the bottom is a player controlled laser cannon. On the top are 3 stone arches. The objective is to shoot as many enemies as possible within 1 minute. Careful-- if you shoot 3 non-enemies, you lose the game.
Every 1-3 seconds, an alien or a duck spawns under an arch and lingers for 1-3 seconds. The spawn rate and amount of time an entity lingers is randomly chosen.
Note: only one creature can be under an arch at a time, but multiple arches can have creatures under them.
The game starts with the screen above. The laser cannon is player controlled, and can move left and right (with the left and right arrow keys). To shoot a laser beam, press space.
The objective of the game is to shoot as many aliens as possible within 1 minute. If you shoot 3 ducks, you lose and the game ends immediately. If you manage to shoot every alien that pops up within that 1 minute, you win the game. When the game ends, either due to time running out or killing too many innocent ducks, the final score is calculated and displayed at the end of the game, using a formula like:
number of aliens killed - 3 * (number of ducks killed)
Please use the images here for inspiration
The game could work well with colorful, high contrast, cartoony artstyle.