Strong Metroid vibes and I love it. The gravity took a bit of getting used to, especially with dodging around enemies, but otherwise the movement feels great!
Even for just a demo level, enjoyed the weapon selection and the enemy variety. My main sticking points would be that the mantling on ledges seemed to be very precise to execute. Also personally, I would have liked to be able to crouch walk by using the shift key. It just feels odd to have a slide button, but then when you're not moving it seemingly does nothing. Overall though, the style, movement and combat are everything I could have asked for. Impressive work!