I think it’s level 5 or 6 that finally introduces simultaneous colors coming from perpendicular directions and then level 7 and 8 that has them coming from opposite directions, which is significantly harder and leaves little room for error (in, perhaps, a slightly less interesting way, however, since the fact that for each of those levels everything comes from the _same_ opposite direction — level 7 horizontally, level 8 vertically — means there’s little chance to recover from a mistake, a new cube arriving just as the old missed one is reaching the opposite side).

Oddly, level 9 returns to one-at-a-time patterns (just a little faster) instead of combining the earlier pattern types. And then the demo ends after that.

Once it gets trickier a few levels in there’s a sense of tactics involved in making mistakes in the least harmful way, and that feels neat.