With the most recent update to the game, the game has been rebuilt in the newest version of Game Maker Studio to hopefully alleviate compatability issues with Windows 10 users.

In the process, some changes had to be made to the workings of the Steam stats, and you may now find that your progress on certain stat-based achievements have been reset. This was unavoidable. Any stat-based achievement that you already had unlocked should stay unlocked, however.