There are several achievements related to Single Player mode. The Bronze Achievement, Dark Elves' Annoyance, requires you to win 15 stars in Single Player. Enemy of the Dark Elves is a Silver Achievement for scoring 50 total stars. If you manage to get all 150 stars, you're awarded with the Platinum Achievement, Dark Elf Extinction. There's also unique Platinum Achievement, Bomb Squad, that requires you to disable 15 Bomb Plants in a single attack on level 50.