This article is considered accurate for the current version (1.0) of the game.
Age of Wonders: Planetfall has 50 different achievements, all using the Steam achievements mechanics. Achievements have no in-game effects; the achievement just pops up in-game, and is then added to the player's Steam profile. It is possible to see the achievements sorted by the percentage of users that managed to complete each achievement by going to the game's global achievements at Steam.
The difficulty of each achievement varies; some achievements are very easy , while some are more difficult. The below list groups the various achievements by a difficulty level as assessed by the wiki editors (uncategorized - UC - achievements haven't been assessed yet).