Hello,
I'm xPathfinder who's the developer of 'Ace of Protectors'.
I've found few desktops have a problem that cannot achieve any Steam Achievements.
So, I'm currently checking the game's engine and trying to fix the codes.
I guess this might be a compatibility problem or a connection problem.
Please let me know these things if you have this problem.
1) Your desktop's spec.
2) Have you lost connection with Steam during playing?
3) Were you offline during playing?
Sorry for the trouble. I'll fix this problem as soon as I get any solution.
* Don't worry about losing your progress with Steam Achievement. When the problem is fixed, Steam and the game will automatically find what achievements you've done and let you achieve those.
Much thanks.
- xPathfinder, the developer of 'Ace of Protectors'.