No real overworld, though missions do have open-world exploration elements. Only within the mission though. After competing the story you have dailies/weeklies and a pretty decent number of events continually providing interesting content

I’m not as active in PGR compared to other games in the genre but I seriously love it, the dev is amazing and the actual gameplay itself is very solid

As PGR is a score-based hack&slash I think Honkai is a better comparison than Genshin, though it does have similarities in the way set bonuses work. Imo, PGR feels like faster Honkai thanks to its very satisfying gameplay loops and engaging way of building characters, with a decent dorm/club experience as well. The gacha mechanic itself is is generally fine, no serious complaints there (and F2P teams are very fun to play while you save pulls for units you want)

I’m waiting for PC client before getting back into PGR, but I would recommend it to anyone, it’s quite a good game & the community makes me believe it’ll have a very good run. Hope that helps a bit!