Baseball Riot

To unlock this achievement, you need to get a region score of 40 or more in region 8. The region score is a combination of your total stars for that area and total balls left. So there are 13 levels, and 3 stars per level. If you get 3 stars on every level of the region, you'll have a region score of 39 points. If, however, you finish a level with 3 stars and a ball left, your score will show as 3 stars and 1 gold ball, resulting in 4 points for that level instead of 3. So you don't necessarily need 3 stars on every level if you can 3-star other levels with one or two balls left. To check your region score, press on the green baseball field-shaped icon in the region.

Below are videos of every level in region 8. Some levels are tough and I was only able to get 2 stars on, but some levels I had 3 stars plus 1-2 extra balls. So don't sweat it if you can't do as well as the videos. I had a different score profile than the videos too. Sometimes you may do better on a level and that gives you leeway in case you can't do as well on other levels.