In Sergio Alonso's shiny new bullet hell shooter, Boss Slayer, Ten alien starships have entered the solar system and you have 12 days to destroy these bad boys before they make their final approach to Earth. The game features an array of upgrades, of which each has a clear, immediate effect and it can be a lot of fun to watch your weak little ship transform so quickly into a beefy alien antagonizer. Boss Slayer isn't an innovative game by any means, but it understands the genre perfectly and serves up a smooth, streamlined gameplay experience.