Mysterious Floating Something is basically an action game with a bit of everything. Think Defender, but with the player assuming the role of the aliens out to abduct humans. The objective is to round up four hundred guests for the greatest party of all time.
Sounds rather strange, but it gets better. Shooting at objects take a while to get used to, and requires a recharge after each use. Fortunately every weapon can be upgraded to reduce the wait. There are plenty of power-ups to choose from, provided that you have enough money to finance each purchase.