Crackdown co-op: HDD required [update 1]

Update: Commenter DjDATZ lets us know that it's still possible to score the co-op achievements by using the Time Trial option instead. So, Core owners may not be able to play full co-op, but they can at least have their achievements.

Crackdown has had lots of hype going for it over the last few weeks. Of course, there's the Halo 3 beta attached to it, but the game itself has earned some considerable street cred itself. Imagine our surprise when we noticed this on the back of the box:

"co-op 2/hard drive required" and "online co-op 2/hard drive required"

We were wary of course, as it could easily have been a misprint. So, we fired up a co-op game with a fellow blogger who was using only a memory unit. Actually, we tried to fire up a co-op game. It wasn't long before he received a message that the hard drive is required for co-op play. Of course, most 360 users have a hard drive, but the fact that Crackdown's co-op requires it -- even over system link -- is important. Sure, it sucks that Core users can't play co-op, but there is something else at work here, too. See, without a hard drive, it's now impossible to achieve all 1000 gamerscore in Crackdown. Two of Crackdown's achievements require co-op play (one for completing a mission in co-op and another for completing all missions). That's 50 points that Core users without a hard drive will never get to see. All 360 games, with a few exceptions, are supposed to work without the hard drive. Yeah, technically Crackdown works, just not all of it. Granted, it's just bragging rights, but we're surprised this fact didn't come out earlier.

Does this issue affect any 360 Fanboy readers out there?