Mercenary Kings is kinda out today, available as part of Steam's Early Access program. I've played a bit (think Metal Slug with a pinch of RPG), and it's pretty great.

It's not finished - you're getting early access, not a final product, so it's missing some stuff - but you'll get that stuff when it's done, which should be sometime around the Fall.

You can get it either on Steam or the game's site, while there's more info on what's missing, what's coming and which platforms the game might be headed to next here.