The game feels great, the movement feels smooth, and the shooting of the spear feels satisfying, the audio is well integrated, and the visuals are amazing! I personally didn't feel like I was in space because the movements are "too" responsive, would prefer I was floating a bit after I let go of the movement keys, Great Job overall! Cheers!! :D
Edit: I read some of the comments and one of them mentioned it felt like water, I think you can place space elements in the scene to make more spacey, like planets or stars.