In a nutshell:
It’s Metroid-vania in a secret underground base/cave system.

What I played:
About five minutes of an already-started, time-limited demo. I wandered the cave system and made my initial infiltration into the base. I didn’t shoot at anything.

Like:
Map: The game uses a grid-based map system both as a HUD element and as the actual navigational guide on the base’s computers. This allows you to quickly connect what you’ve seen in the game world to your immediate goals and location.

Sticky: Your character is a natural spelunker, and you always feel confident he’ll make a jump or at least grab on to a hand-hold. Because of the heavy platforming elements, this gives you a lot of confidence to maintain forward momentum.