Dino D-Day takes a pretty cool premise and puts together a passingly decent first-person shooter. Nazis resurrect dinosaurs, and then people shoot at them or get eaten. It's an awesome premise, and it is fairly well executed. So why the low rating? Mostly lack of content.
There's not just a "focus" on multiplayer, that's the only thing there really is. There's not even a token campaign, and while I'm not completely bot literate, I didn't see a way to make a server and kick around bots, or even just play against bots offline to get a feel for the controls. I like killing bots because I'm honestly pretty bad at first-person-shooters, even if they are sometimes third person, so you can appreciate being a pretty dinosaur.
There's also the problem that in Dino D-Day, everyone wants to be the dinosaurs. It is the primary draw of the game, and I'm a sucker for big lizards (however bird-like they actually were), but there's exactly one allied dinosaur, and it's pretty boring. Having more allied dinosaurs would help alleviate some of this complaint, but at the time of writing it is a major, gaping hole. I played immediately after the game went on sale on Steam, and all the talk was "Let's make a big dinosaur fight" followed by "No, it's Nazis vs. Allies, so the dinosaurs are all on one team."
The servers weren't very busy either, even after the sale.
If I were going to recommend this game to someone, it would be on a night when you're hanging out with friends at a LAN party. There's no shortage of games to play under those circumstances, though. A nice campaign would have given me more than just one night with this game, but barring a miracle I'll probably not be playing it anymore, and I consider that a bad buy, even at $3.
The game itself is fun, but there's so little to it I can't recommend it.