What I would like to see is probably a THIRD person game. Like Just Cause 2 (everytime I play it I imagine how well it would fit JP).
-Open World, on Isla Nublar
-You would have a retractable parachute and grappling hook like Just Cause 2 (to jump from falls and mountains)
-You would be able to do more things than in first person (like climbing walls, or evade dinosaur attacks with spectacular move)
-You would have a mini map with points of interest, like weapon cache and food stashes.
-The whole game would be about survival, while getting an eventual goal of getting rescued.
-You would have gameplay choices to make, like eg: Do I go out at night on the beach to make a fire and try to get rescued (but most predators hunt at night) or do I play it more safely and try to get to that radio tower during the day?
-You would have a kind of "rescue point system"... Every time you complete a "mission", you would get rescue points that lead to be rescued at the end of the game.
-There would be driveable vehicules, some of wich you would have to repair (ie: to get accross a river) to progress the game by finding parts in old abandonned buildings or other wrecked vehicules.
-The killing dinosaur mechanics would be more used as a last resort, and there would be lethal and none lethal attacks, (like tranquilizing darts).
-You would have to use the environment to your advantage. Like trying to lure the T-Rex to a field of heavy raptors population to cause chaos and be able to go trough the field. Or again, climbing on top of a high tree to and using your parachute to get accross that same field.
-You would have to eat, drink and sleep. Find a safe spot (let's say the bunker of the visitor center), use it every time you need to sleep, and when you move to another area of the map, scout for another spot.
-You would have very low health, since the game would not be focused on action. When you are injured, you would need to heal yourself.
-Sub quest that would include finding rare species (you would have a team of scientists staying at a safe spot and asking you subquests)
Ok, I admit it doesn't really look like Tresspasser, that would be a good game to bring JP to a new era and appeal to a lot of player... Making the project more possible.