Ridiculously hard... but fun.
For example, agree with me here, one rocket from a rocket launcher would kill a T-Rex if it struck it bang on the head, yes? Well! Not on Turok, about 30 rockets I shot at the beasts over-inflated noggin, and absolutely nothing happened. Instead, you had to shoot him with a small machine gun for a few minutes, then he went down. But no! The Rex didn't die, once he's down, you have to kill him yourself with a knife! Which sometimes, he gets back up again before you can reach him! Grrr!
But on the other hand, the game isn't too bad. Although it's a pathetically challenging, it is quite fun. I would only recommend it to gamers with patience and good timings! Unlike me, who just runs up to enemies, pressing the 'Shoot' trigger all over the place, lol.