Games which were made especially for CGA did often look really cool.
Possibly not the best example but I do feel like Alley Cat looked great in CGA: https://i.ibb.co/wNDvgzQ8/alleycat.gif
The CGA version of Defender of the Crown also looked quite good for what it was, although most other conversions looked better.
I played that game and couldn't understand why someone would do that. Games on my Commodore 64 looked much better.