Ihaven't played many RPGs or other games within the last 10 years ... But still, looking back, Zanzarah is kind of unique, because it takes away the model of collecting "party members" (seemingly borrowed from the "collectible cards" model) into PC gaming way ahead of its time.
Only now, meanwhile playing Genshin Impact, I find this "collectible ..." concept again - albeit in a very different form. Whereas in Zanzarah, there were only fighting faeries to be collected - each with strengths against other kinds of faeries - which don't act as real party members, in Genshin Impact, the "collectable party membery" have their own inventory, own stories etc. .
Zanzarah is unique, imho, because it brought the CCG model into PC gaming. I've never seen anything like that - apart from the traditional RPG approach to gather or find party members.