Before I comment i'm not picking on you, i'm addressing HL development, you were just the easiest quote at the time.
The reason we picked to develop NNK on Half-life was for a few solid reasons. First and foremost, everyones computer can run half-life and there are still those out there who don't have the luxury of HL2. Alot of those rare few who aren't able to play HL2 are probably the younger players who would be fans of naruto (albeit the english version on their local cartoon channel). And parents are much more likely to spend $10 on half-life, then $200 upgrading their computer so the kid can play. It makes it more accessible for everyone.
Secondly, we know it like the back of our hand. There isn't anything that we have trouble with when developing for half-life. We know all the tricks and we can develop a quality game a lot faster. We havn't had much experience with half-life 2, so having to learn some new techniques would slow us down and undoubtably cause a few problems at some point.
And finally, we weren't setting out to make a majorly complicated game. Half-life's engine provided more than enough for what we wanted to do. The only thing half-life 2 would offer would be a graphical enhancement. But even then with the help of our incredibly talented coder Ryokeen we were able to boost Half-life to look like a shadow of it's former self. And I promise you when we're done you won't even know it was half-life.
Thanks for all the support though guys, I can't wait to see you all in your own servers battling it out.