maybe the game will be available on Steam in Early Access at some point, but surely not in April.
I really don't want to deal with the negativity of part of the Steam users at this point. Plus the negative reviews during the Early Access phase lasts forever which is complete nonsense...
So Steam EA would be more like a couple of months before final release.
However, you can buy the game on ManaGames.com (and I'll get more money as Steam won't take its cut ), and you'll get a free Steam key. It might have a Steam version available relatively early, even if the game isn't sold there before a while.