Valis III is a truly fantastic action-platformer in the vein of 8-bit Castlevania. It features the finest set of playable characters in the series, a trio of heroines who rate as superior to the stars of Valis IV due to both their usefulness and their intangible "cool" factor. It also boasts great music; good graphics; controls that are much smoother than II's and give it a familiar old-school-Castlevania feel; and sophisticated, ingenious level design. While Valis II prides itself on its soundtrack and story and IV impresses players with its visuals and high level of challenge, III finds a way to succeed in just about every area, making it the strongest chapter in the series.
It's clear right from the get-go that this is a high-quality hack-and-slash title with appealing visuals.
Some of the later areas, especially the inundated temple (where you have to freeze enemies and leap atop and from their frozen forms to proceed from one water-enclosed slab of stone to the next) and the ice cavern (with its slippery surfaces and tricky platforming), pose extreme challenges; you'll feel great when you finally get through them. They're tough-but-rewarding stretches that you'll always remember.
Between those dreaded segments are "breathers" in the forms of graveyard and wasteland jaunts. The desert-stage tune is quite catchy and evokes fond memories of Valis II's legendary soundtrack.
Most of the other musical numbers are also very good, as are the cinemas. No more of that "tiny windows" bullshit here... well, not much of it, at least.
Many of the boss battles are conceptually interesting; you'll go from serpent slaying to bell battering.