I'd like to do a small lightgun game. So the mouse should not always be in the middle like in most ego shooters. The player should be moved trough a world and then shoot some enemies at a more or less fixed screen (typical lightgun game style like in Crisis Zone and others).
It would be good if I can just mod a game like Counter Strike, so I can use the models, animations, leveleditor and so on. I did some maps for CS a few years ago and coded a little bit with delphi and the genesis engine a long time ago, so I don't really have that much experience.
Is it possible to mod a existing game the way I described?
Which platform could be used (if possible predifined models and animations and so on)?