Waking Mars is a metroidvania? I picked it up in an indie bundle once, but in the hour or so that I played it came across to me more as a as a point-and-click adventure than a metroidvania... (It's not quite parallel with actual P&C games, buts exploration and clicking.) Maybe I didn't get far enough?
Disclaimer: I feel combat is an intrinsic necessity for any "metroidvania" label.
There's combat, of a sorts, in Waking Mars. Stuff starts shooting at you and/or exploding and/or trying to eat you fairly early in the game (I think it's fairly early, anyway. I've got about 2 hours sunk in the game, going somewhat slowly, and things started trying to kill me about half way through that.). It's actually closer to what you might get if you mixed a metroidvania with a puzzle game to anything else, I say, but it's got most of what I'd consider requisite. Fairly expansive, open map, exploration, item acquisition based progression (sorta'), largely action based -- and yeah, a bit of combat.
And yeah, dust, la mulana (if you're a masochist, anyway
), both good. Fortune Summoners is excellent, imo, but it's also closer to something like the old Monster World games (Or perhaps Popful Mail, if you're looking for something a bit more recent) than Castlevania or Metroid. Maybe akin to Demon's Crest. Also decently brutally difficult after a bit.