Just in case the cover design didn't give it away, this is a delightful spoof/homage to the original Star Trek series. Designed to be played in a single night, you'll need the core Squirrel Attack! rulebook. You can use the characters from there, updated objectives are provided for them or you can use some of the odder denizens of the starship instead, for whom full character sheets are provided.
The concept is simple, although the starship boldly going is crewed by human beings - er, well, somewhat strange and mutated beings including dogs, rabbits and other squirrels as well as humans, some sentient squirrels are - unbeknownst to the rightful owners - also aboard. They have an unwitting ally in the shape of a lowly security ensign who, in classic 'red shirt' mode is about to be sent on an away mission. So the squirrels decide to go along to make sure that the supply of left-over food this disorganised ensign tends to leave around won't dry up!
If the set-up is a bit confusing, don't despair. The opposition draws on several of the better - or is that zanier - of the original series' enemies and monsters. While simple, the adventure can prove a fair challenge and the squirrels will have to think their way through various problems to survive.
All in all, a merry jape; a short and humerous game that ought to play out in a single evening when you are in search of some light relief rather than serious role-playing. Jolly good fun!