Mongil: Star Dive and Girl's Front Line 2: Exilium

F2P games with gacha fanservice!

Mongil: Star Dive

This game is set in a fantasy land where fauna are starting to exhibit violent tendencies and its up to a squad of monster -hunter- tamers to sort it out. Good graphics, excellent animation, an interesting actiony fight system and a good dose of humor are all very welcome surprises in here (as well as being simpler than some of its competitors). The humor especially as the game plays out much like a comedy, including the "taming" process itself. 

That said it is still very "new" with lots of empty unused spaces that you can just tell will be for future content. Also the leveling up system for your random party and their gear, is quite a grind once you hit those level walls which you'll get to sooner than you think. Again, it might just be a case of being new but that killed the game for me.

Girl's Front Line 2: Exilium

This game is set in a post apocalyptic land where fauna ARE violent, just like the numerous PMCs you go up against with your squad of combat "dolls". Yep, its very Ghost in the Shell here with disposable bodies, body parts, and consciousness backups and uploads. Combat here plays more like XCOM and has a puzzle challenge component to it (kill 3 guys in the first round etc) which is neat - though you can also get one support "doll" from someone else and just deploy a level 60 each time to power your way through. :P

The story pieces come in fully voiced (no English dub) visual novel style which I find annoying, but the stories themselves are pretty neat and the art is quite good. While there's also a grindy component to level up your squad its easier to do so here than in Mongil, and because its an older game there are many game modes available to play through even if you find yourself lacking resources or levels to forge on through the main story. Recommended, but be careful as this is an addictive time sink!