The only thing that PiCTOBiTS lacks is multiplayer. Actually, the whole game is a little lean on additional modes. Other than the "music" mode, which works as the jukebox to play your acquired songs and a tutorial mode for learning the ropes of the game, there isn't anything beyond the single-player mode. Still, for a five-dollar game, it's hard to do better than PiCTOBiTS. The seventeen-song soundtrack is itself worth more than that.
The only thing about the game that may turn off puzzle game fans is the difficulty. It gets really hard relatively quickly, which may cause less diligent gamers to give up on the game early on. That said, the game is never unfair, so with enough practice and skill building, any level is conquerable.