Achievements are an entirely optional game system for players who are interested in them. Players who don't engage with this system aren't missing out on any particular rewards. We have found that adding a few new achievements per patch is an additional incentive for achievement hunters to check out the patch and cross off some more entries on their list.
In general we apply the following principles to achievement design:
- Make achievements of many different difficulties, but none insanely hard. We want it to be reasonably possible to complete all the achievements. That's why there's no achievement for getting to level 100 (let alone in a hardcore league). We feel that players are more likely to attempt to get all the achievements if there isn't a 1000 hour one on the list. Six-linking an item is approximately the limit :)
- Some things are very hard to track. Everything that has an associated achievement has to be checked by the game server as it occurs (and potentially stored in a database). Certain things could have large performance impact.
- It's okay to have some achievements that unlock naturally as you play through the game. They make new players feel good.
- Avoid "Do action X times" achievements. It'd be super easy to add ones like "Kill 1000 Zombies" or "Open 500 Chests", but these aren't really very interesting.
- It's okay to add a cycle of achievements (multiple similar achievements) if the cycle is fun and in-line with the encouraged way to play the game. Full-clearing the side areas as separate achievements worked well for this.
- It's okay to add achievements that encourage people to try out certain game features (like "Capture a Flag") as long as you're not spamming the users with dozens of achievements in the first few minutes of the game.
- Some achievements are better turned into challenges, especially if they relate to content specific to the challenge leagues.
The 1.0.6 achievements are:
- Band Together: Join a public party
- Full Clear: Ship Graveyard Cave: Fully clear the Ship Graveyard Cave
While we have a lot of 1.1.0 achievements lined up related to the new content, we're always looking for more ideas (to go in the 1.1.x patches). If you have any good ideas, please feel free to post them in this thread.