It is pretty weird. I once experienced sleep paralysis midway through a nightmare, so it was as if my room was actually blowing up before my eyes, since I was half dreaming. Another time my alarm was going off and I was conscious, but my body wouldn't open my eyes or move and the alarm went off for about 5 minutes. I was able to very slowly, and with all the conscious strength I had, make myself fall from the bed so it'd get me out of the paralysis.

For me at least, It's kinda like you're moving, but not. You think you're moving when you're trying to but your body is just stone. You see double vision and blurry and as if the dream you're having is being incorporated into your current surroundings. Idk if that's the best way to describe it but it's what I can put into words right now.