The official Valve documentation:
https://partner.steamgames.com/doc/marketing/profile

My attempt at an explanation (Reminder: I do not work or speak for Valve):

A game published on Steam gets a "Steam is learning about" tag. The tag gets removed after it reaches a hidden benchmark. If the tag doesn't reach the benchmark within a certain time frame then it gets a "Profile features limited" tag.

These tag imposes these restrictions:
- The game does not count towards Game Collector and Achievement Collectors totals on profiles.
- The game cannot have more than 100 achievements.

If you purchase a game strictly to increase your game collector or achievement totals - then do not buy games with these tags. The game will not count.

:(
Thats not a good news :)

But thx for the check on this one, and thx for the game, had a lot of fun with it!