Kinect Star Wars

If you don't have a skilled co-op partner, the game can be tricked. Complete a ground combat mission solo without being knocked down. During the final cutscene, Pause (left arm at 45 degrees) and add your second player. The achievement should pop as the next mission loads.

Kashyyyk 5 is the first ground combat mission; I assume it's the easiest. (If you feel another is easier, please comment.) Here are my suggestions for getting through without being knocked out:
1. Small droids (B1) and Trandoshans with blasters - wave your arm in a figure 8 to deflect blaster bolts, hack and slash when nearby to take them out
2. Bigger droids (B2) with blasters, Droidekas - jump over them and slash. Keep jumping as needed.
3. B1's with shock staffs - block like in dueling. One successful block will stun them. Slash for a quick kill.
4. Trandoshan's with 2 small swords - keep jumping over them and slashing. It may take several jumps.
5. Missiles - use your Force hand to grab the missile. When you see the blue glow, wave your hand to the side

You'll know you're at the end after you face the Trandoshan's with 2 small swords. After defeating them, pause the game to add your second player. It may even be possible to add an inanimate object, but that could be difficult since the 2nd player is supposed to raise their arm to join.

Thanks for any comments to make this better.