So you expected ten or eleven levels of a molasses slow Gorn chasing you around?
So every Gorn is exactly the same? Face it, the Gorn had to be redesigned for modern audiences. It was going to happen at some point. Much like the Klingons were re-envisioned.
I would have expected the game to be a lot less of a shooter and more story driven, so if they come up with a plausible story about the Gorn, running and shooting wouldn't have been the issue.
Were they not a threat to begin with? For cripes sake you have a reptilian humanoid that can pick up a two ton boulder and throw it fifty feet. Or be hit by something weighing 5 tons going 30 miles an hour and shake it off without injury. Look at what it took to take it down in ENT. Localized gravity at 20G's and multple phaser shots.
What re-imagining needed to take place and have them be dangerous?
Lets give them human or better speed and agility and pretend Kirk would have lasted 30 seconds unarmed with the Gorn depicted in this game. The only reason Kirk or Archer survived is because the Gorn while a near unstoppable brick wasn't a very quick one. So the right thing to do to make it more imaginable is take a walking tank and make it fast and Kirk and Archer still would have survived. The Gorn Commander, Sentinels, Lieutenants would be picking their teeth with Kirk in Arena.
Why not have the binary star system the Helios device was utilizing be near Gorn space and have that trigger aggression? That could have easily replaced the the outpost at Cestus III as the trigger for interaction in the new timeline and kept to the established canon.
It would have made for a better story if it wasn't a couple of Star Trek officers running around shooting everything up and actually had more story driven action that required missions that had action but driven at some for of diplomacy or real discovery.