Robot Entertainment's well-received Orcs Must Die! series is getting on-trend in new game Orcs Must Die! Unchained - mixing in MOBA (multiplayer online battle arena) and CCG (collectible card game) elements with the existing third-person action strategy template to create something new.

The result is a colourful third-person PC game, due this year, that pits two teams of five varying heroes against each other, armed with the kind of traps, spells and abilities the series is known for.

Minions - your army - return, and can be ordered down varying lanes to charge the opposing team and base. Which minions you can send, and which powers and abilities you wield, depend on the cards you've collected and selected for battle.

The result is what developer Robot Entertainment - the studio formed from the ashes of Ensemble (Halo Wars, Age of Empires) - is calling "a fortress siege game". It will be free-to-play.