Better than we expected film about some mercenaries who are sent into some secret experiment tunnels to find some young folk who are half human, half space rock.
Apparently some years ago a meteorite fell onto Russia or Poland or somewhere, and it contained DNA so some nutty doctor injected it into some embryos to create the hybrid(s) of the title.
The boy and girl spaceboulder people have since done a full rude and by time the mercenaries get there, she's expecting a pebble. The delivery goes a bit wonky, the manrock decides this has made him grumpy and chooses to escape, killing quite a few people on the way out.
This is much better than my sarcasm suggests. Although the 'military team discover a bio-weapon' thing has been done more times than I've had crisps (I do like crisps), this one is well made and isn't just people with guns walking down corridors which most films of this type. The acting's good enough, the effects are impressive, and thankfully fairly subtle, and the (unlikely) story is played out well enough to not be laughable.