You control a team of five veteran soldiers and are dropped into an area infested with tens of thousands of scary alien insects that mutate, randomly developing poisonous attacks, shields and even evil clones of your soldiers, so you will have to think on your feet if you want to survive. To counter the massive onslaught of alien you have the choice of various upgrades, turrets and weapons conforming to the standard rock-paper-scissors trope. What seems to make the game stand out is how quickly the tides can turn, like the aliens mutating in way you have no counter to.
Alex Vostrov, the game's designer, wrote up an interesting battle report. He plays a 17 minute game where he disposes of 34.000 bugs and gives a good overview of the constantly changing tactical scenery.
Below is a video explaining the basic gameplay.
You can pre-order the game right now for 25 per cent off and get access to the beta.