Right now you're probably figuring out what to do with your weekend. Instead of visiting the Ornithology Museum or doing whatever other cultured activity you had planned, why not engage in ninja-based mayhem? Hack-and-slasher Ninja Gaiden II has a new mission pack available today for download through Xbox Live.

The mission pack contains 25 new missions in all, split into two sets. One set is "karma missions" where the player tries to rack up the highest score possible (based on speed of mission completion, number of enemies killed, etc.). Xbox Live will, of course, have leaderboards for these scores. The other set, "survival missions," have the player fight off as many enemies as they can with one weapon.

The pack will set you back 800 Microsoft points, or ten bucks. According to Gamerscore Blog, you'll also get 10 new achievements with the missions to give you a sense of accomplishment after your weekend filled with ninja-ing.

Update: Whoops. The DLC, as it turns out, was plagued with freezing issues so it's been pulled from Live Marketplace. Gamerscore Blog says it should be back online on Monday.