Due to lots of people bugging me about it, I’ve added support for editing statistic values to Steam Achievement Manager.
You can download the new version of Steam Achievement Manager on its page.
Also to address some concerns about people asking about Left 4 Dead achievements. They’re not “persisting” in-game when you unlock them in Steam Achievement Manager because there are statistic values tied to them, and the game verifies these when it lists its achievements. It has nothing to do with SteamCloud (that’s not its purpose!).
New games listed as of 5.0 (I added these before 5.0 but had not posted an update):
- Killing Floor
- Plants vs. Zombies
- Zeno Clash