There shouldn't be any beating around the bush when it comes to ZOE. If you liked the games, watching this series and the OVA is highly recommended.
It's a very good spin-off that fits nicely into the continuity and expands it's lore.
However, if you are unfamiliar with the games - it's just a solid adventure title. It involves characters that change and evolve, cool mecha action and the level of tragedy that will most likely leave you satisfied. Despite not being deeply dramatic/psychological as similar looking shows tend to try it's still original.
Also unlike some other adaptations done without regarding the newcomers ZOE Dolores doesn't require you to be familiar with the original source material. Everything is explained and some of the events even expand on the subject matter present in the games.
It's sort of a hidden gem. I really suggest you to check it out if you just want to have a good time.