One bug I noticed is that while on the planet screen, you can only buy one building per turn (as intended), if you quick-buy buildings from the civilization manager, that restriction is currently non-functional.
Also, you can currently demolish buildings you should not be able to, like the Weather Control Centre and Biosphere Modulator. This has the game-breaking side-effect that planet quality can be increased up to the theoretical maximum of 72 by alternately destroying and rebuilding either of those two buildings (PQ doesn't decrease upon destruction of a modulator)