Dino D-Day is not worth any amount of money. Don't buy it. It may seem like a fun novelty at first, but the novelty wears off after about 10 seconds and then it's only a diluted, buggy, mediocre shooter.
Totalbiscuit reviewed it here:
http://www.youtube.com/watch?v=SxxW39P9af8
I was initially going to say "it's worth $5 at most", but I realized it's not. Even if it was free, it still doesn't change the fact that it's a bad game. Why waste any time at all playing it when there are far better multiplayer shooters out there? You could be playing TF2, or HL2: Deathmatch, or something in the same vein. They are much more fun. /rant