So if you love a fun and challenging shooter with a clever mix of styles and a killer assortment of boss battles then Nano Assault is definitely worth checking out. While 32 levels might sound like a lot, they are surprisingly short and fast, and competent gamers can blast their way through the Story Mode in 3-4 hours, but with the endless appeal of Arcade and Boss Rush modes there is enough addictive old-school arcade goodness to keep coming back for more microscopic carnage time and time again.