Hell yeah would I play it.
This is almost exactly an idea I had back in the days when I owned my first PC (damn, I sound old!) somewhere in the early 90’s.
But: Definitely no MMO. First I don’t like games that tie you to the ‘net and second: There is no city big enough to allow multiple assassins in it. Although it would be funny when you get a contract and the side-note: Oh, 3 others are on it. Go fast!

@ Matt`:
You could also make repeating a particular method progressively harder. For instance, as the town gets to know a sniper hitman is in town, guards would first watch rooftops and windows, then search persons carrying suspicious bags, patrol the roofs, hire helicopters to spot you, train their bodyguards with “VIP-preserving” reflexes, use decoys, hunt for weapons suppliers, and so on. For chameleons, the security protocols would be gradually increased, with IDs, then IDs with pictures, constant radio contact, retina scans, and guards would become more and more suspicious of their brethren. All these obstacles should be defeatable but sticking to one modus operandi would require some very well studied plans to succeed. It would also make the town feel like it’s reacting to your presence, and that’d be great.

I think I’d play this, but as noted, it might be hard to add challenge/variety if you can use any method you like.

Sure, you could set up an elaborate Rube Goldberg machine of death, if the game physics is good enough, but it’d be easier to wait for the mark to walk by a window and drop him with a sniper rifle.

Maybe if you made more of a thing out of the additional requirements – your clients have demands they want fulfilled, you have to be a little creative about how you make the kill. Or you’d need to make it a little more instanced; set things up so that you can’t use the easy method every time.

It could be done, if pulled off to be everything we might hope for it’d be pretty epic, but it’d be a tough one to make work.

I’d play a game like this. In fact I’d play anything close to Hitman, it’s a shame this genre hasn’t become more popular : planning a single silent assassination is much more fun than the genocides you do in FPSs.

I don’t think your perfect game would be much different from Hitman as it is, at least not for the actual hits. Interesting hits would have to take place in special locations and targets would need complicated schedules and lots of guards. If you can just get on a roof and snipe every target down, or rig his car, it becomes repetitive and not much fun. Basically, it would be GTA for the time inbetween missions, and Hitman the rest of the time.

@ IceBrain:

I played GTA Sand Andreas and I didn’t particularly like it. For one, you couldn’t really scout or plan your missions. The enemies would just spawn at a certain area where they never were before. Many missions had one and only one correct way to do them, and you had to discover it by trial by error.

The robbery was a mission/mode. You couldn’t just go and steal shit from a random house. You had to find the right car, drive to a specific marker on the map, and then carry out generic boxes out of there.

This is very different from the way you looted in Oblivion: “Oh! A mansion. Let me see what’s inside”.

What I want is this:

– persistent open world from Oblivion with pre-existing NPC’s that don’t just spawn when you enter some trigger area

– Conversation dialogs from a Bioware game

– Open ended driving from GTA, but without required stunt driving or street races

– Hitman game play in which you can knock someone out, take his clothes and infiltrate. I want to have a garrote, poison syringes and etc.. I want to be able to drop pianos on people, rig their cars to explode, put rat poison in their oatmeal, push them off a balcony, etc…

The only part of GTA that I really liked was the open driving. But I could live without it if I got an Oblivion and Hitman fusion that would just require me to walk and/or take taxis for fast transport.

Well, I believe that GTA (at least VC and SA) is already somewhat like that, only very simplified and dumbed down.

In SA, you could get a truck and rob people’s houses in the middle of the night. You also have more than one guy who gives you missions, and some contact you via cellphone.
You can also trains your weapon skills:

For each weapon, the skill level will result in different upgrades, as a general rule of thumb; reaching higher skill levels will increase the rate of fire and accuracy. Also, with some weapons, getting better skills will give CJ the ability to fire while moving and strafing.

Mission “liberty” is also present: I remember finishing a mission by, instead of walking and killing all the goons, simply dropping a helicopter on the target :P

So it’s not so much a game fusion, as an “advanced” GTA, imho.

What I would play is something like a GTA MMORPG, but with no NPC quests like most mmorpgs; something more like an EVE model, where each player can give assignments to others players.