Coming a little late to the game, I have spent the last two weeks trying this out:

GTA 3 V1.1 for PC

After Finishing all of Joey Leone missions, all but the last Luigi Goterelli missions, Marty Chonks missions, I had to cheat to finish Taking Out The LaundryBomb Da Base Act II , before I could get to finish any of Salvatore Leone missions. 

By then 5 tanks were stuck in my map, one in the water refusing to die... Moved them east of save base.

I had up to 4 star warrant and taken out 3 helicopters, 4 police buss's and a plethora of local cops. Two Local gangs (Liberty City TriadsDiablos) make it difficult to even drive around without guns blazing. (Though I've taken out more than my fair share of them both) 

My first impression is "Carmageddon II: Carpocalypse Now" with missions. Especially with the 3d graphics and certain break-away body parts ( legs heads pop off like "cat & mouse" points on CII CN)

Changes I've wanted to add to the GTA3 wiki:

In cheats gunsgunsguns isn't the full gun cheat, type "guns" twice and every time you type "guns" after that all certain weapons bump up by their respective quantities. Rhino tanks and their locations stay during save games. (even if sunk in water) (but where to put this??)

Health increase by prostitutes is up to 25-50 (haven't managed the exact # yet) which can bring your health above 100. (GTA III tops at 125) you can re-use the same prostitute by driving away before she gets out, and stopping again in a "secluded" spot. Hilariously, the increase goes up as fast as the car grinds down. You can stop early by exiting car, or driving.

Misty is technically not an game acting prostitute, since she doesn't help you out in secluded spots like the others do (or maybe just not for me?). Luigi Goterelli warns you to keep your hands on the wheel, which of course made me wonder, what if I don't? But nothing happens if you take her to a secluded spot.  Misty is also fairly strong & built, I've seen her kick a fighting pedestrian halfway across a road, I hit her with 12 fist punches before she died. In Luigi's Girls, Misty follows you and fights anyone you attack, I think she defends herself, but haven't pushed it yet. She stands unresponsive (but reacts to hits like a rag doll) if you still have the blue arrow above her. (walk up to her instead of pulling a car up)

Car repairs: It's a free to park your car in your own Safehouses in GTA III, it's fully healed when re-opened. But no color change and no police level change. People stuck in the garage may stay if you save that point. (though missions don't save partway through) Pay_n_Spray#Trivia