Players who own Xbox Live Arcade versions of games by The Behemoth, developers of Alien Hominid HD, Castle Crashers and BattleBlock Theater, can unlock items in the latter two games, according to a press release and a blog post from the developer.
Those who own the full versions of both BattleBlock Theater and Castle Crashers on the same console can unlock the knight from Castle Crashers in BattleBlock Theater. The "Can't Stop Crying" DLC, which includes a new playable character called Hatty, unlocks in Castle Crashers after players earn an achievement in BattleBlock Theater. Owners of the full XBLA versions of BattleBlock Theater and Alien Hominid HD can also unlock the latter game's Alien in BattleBlock Theater. You can learn more about the "Can't Stop Crying" DLC in the video above.
In addition to the unlocks, Alien Hominid HD and Castle Crashers are on sale for 800 Microsoft Points ($10) each until this Thursday, April 4. BattleBlock Theater is set for release tomorrow, April 3.