Been out in beta for a month or two. Open beta is not Asia only. I tried it for a day and this game is crap.
The graphics are ancient and it's extremely cash shop oriented. Producing units and upgrading takes time, but you can buy items to speed it up and give you tons of advantages. You can play without the cash shop, but you might as well just get the classic HOMM games if you want a better experience.
Feel free to try it for yourself by visiting the official website 91.com (sign up for an account, apply for beta). But for me, it wasn't even worth the download time.