LotharBot made a series of the five platonic solids. The other two I liked were Monkey Bars (a cube, with all weapons) and Octave (a plasma-flavored octahedron). Tetrafusion was the only one that really seemed to catch on, though.
You could also try Three Sisters (and others in the series). Halls of Iconia would qualify under the 4D clause.
Maybe Vertical Dragon? It's a weaker example, but I'd think that would count too.
I know there have been others, but sadly, non-oriented levels have always been a bit of a gimmick. If someone would make a level that was a solid, reasonable level but which simply lacked orientation . . . that would make me very happy.
Maybe some day I'll make it myself . . . still looking for that perfect level, you know? Three sisters is close, but it still has a lot of orientation in it.