Ouch, if I got to 280 and it didn't unlock, I would probably delete the game on the spot. I'm just hoping I don't get a random reset or no moves glitch. If you save on 279, can you complete 280 and switch of the console if it doesn't unlock, then try again from 279?
I've beaten Endless twice. It glitched on me and the achievement didn't unlock. I've been told that it might be something like "Seriously" and you'll need to play 20-40 levels past 280 to unlock it. Because of the way that the levels get longer as you go, level 200 is about the halfway point, so you have quite a way to go. Good luck.
Alright, I see what you mean now. I'll get in touch with original author of the guide and see if they can fill in the missing information and then we'll fix the guide. Thanks again for bringing it to our attention.
Thanks for the feedback on the LotR: Conquest guide. I havn't played the game, so could you be more specific for the problems with the last two achievements that you listed? I fixed the first two, but I don't want to reactivate the guide until I've gotten everything fixed. Thanks again for catching the mistakes.