Thank you for the comment! ^_^
"What gameplay time do you estimate for release version?"
I've never been quite sure of how to answer that. Would it be the expected time for a first player, which might vary significantly depending on how a given player fares at the various challenges? Or the time for an experienced player, which is likely to be far less than for a first-time player? 100% completion, or minimal?
At a guess, I'd say that I'd expect a non-expect playthrough to take a few hours, all told--but I don't yet have data to back that up, I'm afraid. As I said, it's a guess.
"Reminds me of Mist a bit, with those puzzle elements. :)"
Thank you! That's high praise, as far as I'm concerned! ^_^
"And will you have controller support? Should be nice for such type of game."
It already has controller support. ;)
(You do have to switch manually to a controller profile in the options menu, or bind the controls yourself if a suitable profile isn't available; the game is a little old-fashioned when it comes to handling such things!)