I've now implemented PUZZLE MODE PROGRESS SAVING!
...complete with a message on the level previews to show those levels with games in progress/saved, if TetraLogical finds a save state for the previewed level and difficulty settings! (ie. Puzzle Mode, Hard, Level 14, etc)
So, NOW, if you've placed at least ONE piece and started your game, then the QUIT button will become a SAVE AND EXIT button, and you'll find that exiting from an unfinished puzzle game by either pressing this button, or by clicking the CLOSE icon at the top right of the screen, will now create a save state/snapshot for it. Going back in to try any SAVED puzzle again will automatically reload it at the exact point where you left it!
ie. If you only have 5-10 minutes to play, you can still have a blast at progressing a particular level, then whenever you play a move, it will update the save state, ready to continue next time, if you have to exit the game.
If you want to take time to try and fully solve the CRAZY or HARD levels, for example, you can now take ALL the time you like, WHENEVER you like, figuring out the best moves, chipping away without needing to set aside a huge chunk of time to think about completing a tough puzzle in one go!
Enjoy the new SAVE functionality, guys!
PS - Pressing the RETRY button will CLEAR and restart the current level, and can still be pressed if you've broken your current attempt, to quickly start another fresh attempt... :) (PS - If you choose RETRY, and simply exit without playing any pieces, then NO save state will be saved. Good for clearing any 'game in progress' markers for levels that you've started by mistake... :) )