Mastery #12 Breath of Fire IV
I am a huge fan of the series but have primarily played the first 3. I felt like this was a very well done set that got me to really experience the game and see all it had to offer.
The amount of mini-games is excessive but honestly most of them just took 30 minutes of practicing to get whatever score was needed for that particular cheevo.
The only exception is the rhythm mini-game (Kecak) that everyone in the forums complains about. It really is pretty brutal mainly because it seems like the timing window is incredibly strict and possibly has some emulator-induced lag that really makes getting the high score challenging. There are a ton of helpful comments in the forums about that one. The piece I'll add is make sure to turn off things like widescreen patches and set resolution back to native and turn off dithering etc. Duckstation has a "Safe Mode" toggle button that makes it pretty easy to temporarily play like this while easily being able to get back to your optimized settings once you're done with the mini-game.
Now on to the collect-a-thon to earn that Gex badge!