After 25+ years of video gaming, playing sports, and picking my nose... Oh and a little research and practice the most consistent recipe for producing fun was a combination of tense, realism, unpredictability, comfort, and enlightenment. I didn’t put comfort in the title because I think its kinda overrated by designers but its very important.
Copy and paste
Intensity- Usually requires elements of unpredictability. Produces excitement and addiction.
Realism- Inane in a vacuum. A versatile tool when combined with other elements. Can provide comfort, consistency, justifications, fairness, enlightenment and challenge.
Unpredictability- Requires realism for the sake of fairness, can produce intensity and challenge.
Comfort- Difficult to quantify and produce. Brands and controls are common stimulants for comfort. Without it everything else can break down.
Enlightenment- A combination of accomplishment and learning. Usually a product of comfort and challenge. Addictive
So that’s the criteria. These are the suggestions.
A free 1st person camera.
I don’t know why more games don’t do this. If the PC is knocked upside down or horizontal then the camera should be upside down and horizontal. The camera should stay locked with the PC’s eyes. Mirror’s Edge did great job of this. When you rolled in that game the camera rolled with you.
Coup De Grace
One hit kills should be in the game even for certain lower lvl combinations.
Give the assassin types a chance to slit a throat when they make their stealth checks.
Location damage
Let head shots be head shots. Borrow from New Vegas
Less combat
The law of diminishing returns isn’t favorable to game that’s a fraction of the size of TES games. Less combat adds intensity, unpredictability. Less bandits more farmers. Less levels means less hp. Less hp makes damage more intense and can be enlightening when you make short work of opponents as apposed to battering sponges.
Offered surrenders
The people and creatures that you fight in Oblivion are too brash. They are ready to die too easy. Let them flee, beg for mercy and offer a noble surrender, or bribe. Mercy could improve rep while a lack of mercy could make the PC more intimidating. Good opportunity for choice and consequence. This adds comfort, realism, and enlightenment.
Realistic damage
Again borrow from New Vegas. The damage sponges of Oblivion were not fun. Less hp for the PC improves intensity and reduces the necessity for level scaling when the higher level creatures are more vulnerable to a good set of archers, and higher level PCs are more vulnerable to wild animals and armed banditry.
Wrestling, grappling, biting
Choking, body slamming, headlocks, submission techniques, jumping on the back of a large creature is all as fun as it sounds. Implement that stuff at lower lvls and improve it. Don’t force someone to be lvl 15 before they can do a headlock.
Non-lethal combat
Bar fights between citizens are fun. Stop killing citizens over petty theft.
Real Adventure parties
To slap Bioware they have to be 6 man parties. There can and should be a strong solo element. Save that for higher levels. Let the lower levels join a party/gang/ merc unit etc. Prove that you can do it in 3D with advanced path finding that includes stealth, AI that doesn’t rush pell-mell to its death, mission planning, ambushes, and other tactics. Do that and you will also slap the rpgcodex which gave Oblivion a bad review. Another thing that might help is to add a negative hitpoint option like D&D so you can save people that are fallen. This would add comfort, reduce the necessity of scaling lvls, and add realism
Great battle tales
With less battles the battles should be more memorable. There should be hugs, high fives, kisses, after major battles. Identify the major battles and have the companions remember them and tell stories about them.
Limit Potions
Health positions are almost a cheat in Oblivion especially with the high hp. Make them rarer and more expensive. This would be balanced with the reduction in combat and hp.
No level scaling
Level scaling sacrifices everything for comfort but it fails to maintain comfort when you are fighting Rambo Goblins and Daedra on major highways.