Even by the time Sins of a Solar Empire folks Ironclad Games announced their MOBA Sins of a Dark Age [official site] in 2012, the genre was a little overcrowded. SoaDA was originally billed as a MOBA/RTS, but later dropped bits like base-building. It's still trying to be more ambitious than you average Dote 'em up or Loller, though.
Now, after a lengthy stretch on Steam Early Access, where it costs $5 (and it was $25 for beta access before that), Sins of a Dark Age is out free-to-play for all to manage lords. It's on Steam.
We're long past the point where the concept of MOBAs need explaining, aren't we? I realise there are a few people who'll wander in and say "I don't even know what a MOBA is but I think they're silly", which is the PC gaming equivalent of an uncle saying "What's this noise you call 'music' nowadays?", and some folks new to gaming won't have learned yet. However, with MOBAs pretty much the biggest games this side of Minecraft, it'd be more appropriate if I went around explaining "An FPS is a game where you shoot men in the face until they fall over" or "An RTS is a game where you click on men then click on other men to make your men shoot them until they fall over."
So! How does SoaDA look in the MOBAsphere? Well, all heroes are unlocked for all, which is nice. Matches spawn RPG-y quests and objectives as they go, which are controlled by an AI director and offer extra bonuses. Gold for killing creeps is shared a little between nearby teamies, though the killer gets more. Heroes can be customised a little with 'Hero Gear', changing how certain abilities work, which is a persistent system separate from in-match items. Beyond that, hey, it's a MOBA, and you don't need me to explain how it works. And, like the rest, they Ironclad swear blind it's not pay-to-win.
Hey, look, here's an old, old trailer from its Early Access days, in the absence of anything newer: