Black_Jack (./114) :
May I suggest u, if didn't already done, to create multi-level screen (maybe 2 or 3 on top of each other) with secret areas and mid-bosses?
Like in "Devil-Crash" kind of games (that was a flipper game actually but I think it could fit here as well).
I have tried to follow your suggestion and have made the background tile layer scrollable, with some kind of a "camera" which follows the ball sprite.
Scrolling the shrinked background tiles works but updating the position of all the animated block sprites (216 sprites in total) each frame has slowed down the game too much.
But anyway, I have used the "scrolling shrinked tile grid" for something different - a 20 x 20 pixel tile background for a Top-Down RPG.
Not sure if that is a good idea since it is quite spite wasting (34 instead of 20 sprites for a full screen) but on the other hand it allows to use tile graphics with a better resolution compared to the usual 16 x 16 pixel tiles.
Only 4 x 4 pixels more per tile sound not that much at first but it means a lot when dealing with pixel art graphics.
I have made a quick mock-up with a little witch walking in a scrolling dungeon room.
The tile graphics are exchangeable and are "inserted" from an external tile set graphic thanks to HPMAN's SC1Put method (I have used the "Tiled" editor to build the room array).