SimCity was also released on the CDTV.
Don't know the difference with the 512k version, but it looks different though and seems to have added scenarios.
The controls are based on the CDTV remote controller and use full-screen menus (that slide over the map). Also there is music (per every scenario) as CD-tracks on the disk. The game can be saved to a disk (using external disk drive) or to the CDTV specific RAM cards.
Looking at the Lemon Amiga games section on the SimCity (512 Kb normal version) the CDTV version has much more colourful menus and icons. The standard-Amiga version looks much more dated. Also the seen reviews on the two versio seem to prefer the CDTV version.
Just based on the visual points and good controls (with the CDTV controller) I would rate the CDTV higher.
I wish SimCity 2000 was faster (and wouldn't use interlacing), it would have much more deapth to the game.
Slightly off-topic, but still in the SimCity theme:
SimCity 5 is rumored to be the next game in the SimCity series, to be released sometime in 2013
