I can get 5 complete puzzles achievement, but not 10, it won't unlock.

I am enjoying the game, however only "Success!" and "FIVE 3-Star Puzzles!" achievements are unlocking.

If you're reading this it means you were kind enough to glance at my little jigsaw game and maybe even played the demo or added it to your wish-list. In any case, thank you! Constructive feedback and ideas are more than welcome so please feel free to start a thread or reply to one and I'll endeavour to read and reply as soon as I can....