Well, I just played against “Easiest” AI twice. The achievement didn’t register. I clicked Reset button, then set Arabia, Easiest, Conquest, cheats disabled. The achievement is borked. I guess my play against “Hard” was probably the same problem.
Here’s the ultimate workaround for this issue:
After finishing the game, and seeing the “You’re victorious message”, you MUST go to the statistics. Do NOT click on “Return to map”.
Some achievements trigger only after going to the statistics screen for the first time. They don’t trigger when you finish the game, go back to the map, and then go to statistics. So far, I’ve found the following achievements to be bugged in this way:
- beat the AI on X difficulty
- collect 100 relics
Hope this helps everyone.