* If you recently got the newest update (mid-September 2016) then the total number of Winter levels jumped up to 285, giving you a total number of possible stars at 855. This means you can 2-star every level and still get the 500 needed for this achievement.
The minimum number of levels to get 500 stars ranges from 167
(if you 3-star every level) to 250
(if you 2-star every level). You will likely be somewhere between 167 & 250 when you hit 500 stars.
I hit my 500 by level 232 on the 360 version and level 224 on the Xbox One version:
Always shoot for high scores. Here are things that help:
- Make and use power crystals (windchill, iceberg, glacier)
- Finish levels with lots of moves left
- Combo moves and cascades (side-by-side matches & matches that occur immediately after your initial match)
- Speed multipliers (make several matches in rapid succession)
If you can't earn stars by skill alone, then you can use/buy the various powerups & helpers the game so greedily offers. It's possible to spend a small/large fortune on this game if you're not careful. Do not allow your kids the ability to buy things on your account. Unless you're rich.
Every day, there's a chance to get a reward. It comes in the form of a 3x3 grid of covered squares and you pick one square to uncover the reward underneath. The problem is, this feature is glitchy - plagued with server issues and failure to work when it should. When it does work, you have a chance to earn 1-3 lives, a snowball, powerup or ice pick. This should happen right after you select Single Player mode from the menu screen.
Since you only get 3 stars per level, the minimum number of levels you need to complete for 500 stars is 167. So any levels you get less than 3 stars will likely bump that number up past that. The current maximum number of levels seems to be 195. If you 2-star all 195, that equals 390 stars. So on top of that, you'd need to 3-star 110 or more levels depending on how many 1-star levels you had.