Ok, theres a few ways you can do this and the choice is obviously yours. I'm a developer but I work 12 hour days 7 days a week, so I'm just going to offer an opinion or two.
I've never played the game but I generally know what I'm talking about
1) Fully web-based.
Web based means platform independent (mac, pc, linux). It can be flash based, and take place on the web server, meaning you can allow people to play against eachother or at least keep a central score database and have top players.
You charge an entry fee for a login, or require a mandatory minimum donation to NS, etc. Then you can have small token fees like, say... $.50-$1 to enter into comps or ladder matches, all online, all on one server.
2) Console, with SDK
You buy the SDK from whatever platform, and adapt the game. This will require usually a complete re-write, lots of money, and tonnes of work. You simply charge for the game like anything else
3) Console, without SDK
You make a console-bootable self-contained Linux distribution on a CD, that boots itself and then runs the game under the Linux environment on the console. You avoid the SDK, require only minimal changes to your code, and it can be platform independent if it is a web-based game (ie, linux starts a web browser, connects to the server to either play or download the most current version). You charge for the game itself, or by access, since there may be legal issues charging people to recieve a linux distribution (which is GPL).
4) PC, closed source
You create the game as a normal PC game, where all development is done by the dev team. You compile for a certain OS. You sell the game normally or on subscription based
5) PC, Open source
You create the game and release the game itself under GPL, making it open source. Your dev team does a lot of the work, but the community can make suggestions to the code and you can incorporate them. You sell the game on a subscription service where people can pay to play or just pay to enter special events or contests etc.
6) Handheld game
You create a small, cheap, but fun and playable game geared toward a handheld console (ie Nintendo DS/lite/etc). I believe DS allows you to create cartridges without purchasing any official SDK, and if you do have to purchase it, it's affordable. Development for DS in particular is easy, and cheap. Depending on what the current game is written in and what libraries it calls on you might only have to make minor adjustments.
I personally would use the web based option, because you have
a) no cost of media (cartridges or CDs [bluray is expensive as shit])
b) fluid development (as you fix bugs and add patches they are instantly available)
c) subscription control (you can tell who pays, whos playing, who actualy plays regularly, etc)
d) cheap/free development costs (if you can adapt it to flash etc)
e) easiest multiplayer capability (since theres one version of the game, on one server, everyone plays together, instead of itnegrating 5 different consoles or PC platforms)
f) Works on anything with a web browser.
