Here is the solution for the anniversary level! This guide provides screenshots of the solution and a step-by-step walkthrough.
Full Solution
Step-by-step Walkthrough
Starting off on top of the cake:
1. the present next to the candle (pink-green whipped cream)
2. the red candy in the box underneath the candle (blue-coloured whipped cream)
3. the red-coloured whipped cream on the corner of the cake (strawberry)
Going left, turning to the next side, look at the lowest layer of the cake:
4. the star candle on the left of the fairy lights (blue-coloured star)
5. the small blue candle next tot the ladder on the right (moved)
Going left, turning to the next side, look at the middle layer of the cake:
6. the blue uniform on the cheerleader on the left (uniform is orange)
Looking at the lower layer:
7. the candy cane on the left, in between the wooden sign post and the alien (orange-coloured candle)
8.the white man leaning on skater dude (turned around)
Going left, turning to the next side, look at the cove the middle layer of the cake:
9. the vat, next to the opened chest and left of the latter (open vat with blue content)
Look left of the cove, on the middle layer:
10. the top of the light blue giftbox, left of the fairy lights (turned around)
If you have found all the differences, you will get the achievement!
By Ruhinna