Im DLing now. It doesnt say anything about "New in this version" in the iTunes store, hopefully they added more levels cause I beat the whole thing in like 2 hours.
They won't be adding more levels to the game out right now. They will be adding a new episode though (Entry 2) with more levels, which will be a separate game, and will probably cost $3.99 as well.
There won't be one, ever. They designed this as an episodic series, more levels are reserved for Episode 2, which will not include the levels from Episode 1. That's why the game is so cheap. You'll never see extra levels added to the current Episode, because that's not their business plan.
And BTW, just because one person beat it in two hours, why do you think you will? The game is based around puzzles, if you are an amazing puzzle solver with decent reaction times, the game will be quick, yes. But some of those puzzles are quite mind-bending at first.