Got in the playtest and been playing over the weekend. Starts slow like any old school MMO. Seems to pick up. Looks like there will be lots of characters to unlock if the blank spaces in the codex are indication. Movement feels really clunky, maybe by design. The input feels like it lags (on controller at least) after you release the analog stick and your character will continue doing an action (move a square over, etc). Its my one gripe about the game so far. Everything else feels fine. Combat is slow but methodical. You have to be careful not to pull too much in your adventures (kind of like dungeon instances with 3 people). Think there are bosses and other things I haven't experience yet. Only in Chapter 2 on the story and have only played the old mage guy.
Don't know if there are healers in the game, but there's definitely tanks, and the game seems to enforce that by the stat boards at the end of adventures. There is damage done and damage mitigated. Don't think there was a heal stat (might be dumb and not remember?). My guess is "healer" is rolled more into tank survivability then keeping the group alive type of stuff.
Digging the pixel art. It feels like I'm playing FFVI/Secret of Mana MMO.