Any Earth Defense Force game is pretty much an early 2000s game with a progressively better coat of paint.
Ys 9 had progression, town feel, sidequests, camera cuts, etc of a 6th gen JRPG. Same for 8 but that originally on the Vita so it makes sense. 10 looks like its using a new engine.
And a deeper cut, Monster Menu: The Scavenger’s Cookbook. It's like a portal opened up from 2010 and spit out a PSP game, something like Z.H.P. Unlosing Ranger VS Darkdeath Evilman, that runs on modern machines.
Their adherence to older design leans towards a net positive for all 3 IMO, some QoL problems aside.