The two non-demo files have received some major upgrade :

there is now a RELAXED difficulty, which removes any time pressure. Build at your own pace and chill out.

Exiting the game now saves the state of the play field (minus the bonis!), your score, lives, etc. This happens for each difficult/game mode separately, so you can have up to 7 save games (RELAXED can only be played in NORMAL mode). You can then resume your game later on or start a new game from the main menu.

Enjoy