GTA bits come from having the free roaming city where you can kick the crap out of anyone you want,similar story to VC,police & mob meters (though there hasn't been a mob meter since GTA 2) and customization of characters that's a lot like SA. Much more customization of things though even plastic surgery to change their whole face. It actually matters in this as it will lower the meters. The somewhat exception to this is Gina. Due to her tattoos certian outfits raise the meters but you can have them taken off. Chances are your character will look absolutly nothing like what you started with.
Suikoden part comes from leveling up and having a massive amount of characters to recruit. Also your health is in HP form while on the menu. You learn new moves as you level up.
The gameplay style is like Final Fight but slightly differnt. There'll be group battles where you and any of your party members (can have 2 with you at a time) take on a bunch of people and then there's the one on one type things that sometimes play out more like an elimination match in a fighting game. These fights have a pride meter. If you empty out your oppents meter you can press a button to grab them by the neck and then it gives 4 options: recruit,rob,interrorgate or beatdown(wich is like a fatality and will raise your police meter to the max). If you do any of the first 3 you can fight them again later. They actually have damage modeling and it's what I had expected out of Tao Feng. Some enviroment interaction like slamming people face first into a wall. It's almost MMA-ish. You can mount people once they're knocked over and there is some armbars and stuff.
The gameplay,story and ideas are all really good. It does have it's share of technical problems though so if you think that kinda thing is important you may not like this. Sound and graphics aren't all that great and it froze up ocassionally.
If you do like the game it has tons of replay value. Each of the differnt shops in the game has various upgrades,there's 50 side missions,100 characters to get in your party,5 main characters,I think there's 8 endings,there's a rep system that changes unlockables you get for finishing the game and influences the endings as well,a VS. mode and I'm probably forgetting some more stuff. It has a new game + type thing where you blacklist(people you've recruited) and money carry over.
It's a lil on the easy side for most of the game(chapter 5 and the last chapter are pretty hard),not really liking the save system and you can very easily miss a lot of stuff,that's the only real complaints I have with the gameplay.
Overall I'd give it 8.5/10