Throwback XCOM successor Xenonauts 2 leaves early access in April, though the developer says the milestone 'doesn't mean our work is done'

XCOM 3 may still be nothing more than a glint in Firaxis' compound eye, but Steam's digital walk-in freezer is bursting with alternative tactical lifeforms to dissect. These range from Julian Gollop's own attempt to modernise XCOM in Phoenix Point, to The Long War creators' absurdly complex Terra Invicta, which blows out X-COM's alien invasion concept to grand strategy scale.

Then there's the Xenonauts series, arguably the truest attempt by a modern dev to replicate the look and feel of Gollop's X-COM: UFO Defense.