You're missing out if you don't check out the first one before the next console refresh renders it too dated to enjoy. Still probably one of the best post-HL2 first person shooter experiences, especially if you take the over-the-shoulder games out of the equation.
Without trying to sound snarky, are there a lot of folks that buy the games without playing them? I'd say I have tried at least 80% of my backlog even through I've only finished about 40-50%. Most of the games I have yet to play a couple of minutes were bundled (Humble or a Tony bundle) or $1 or less.
Sadly, yes :( And I am one of them. It happens with console people too, though it's a lot easier when you don't need to find space in the house with tons and tons of game boxes like the digital world.
For me it started with the PS2 I got in college.
Prior to that I played ever game I bought to death... PC, N64, Super NES, etc.
I ordered a PS2 in 2001 I think with one game at the time (Jak and Daxter) and played it 100%.
Then some time in like 2003 or 2004 my bro in law introduced me to this site and it was game over. I got like 20 games at the huge Circuit City $5 thread and the backlog started and has only grown. For my consoles now, I try to cut back so my PS3 and 360 backlog isn't insurmountable and I've played almost every game I've bought at least once.
Now for PC, my problems started in 2009 with my first Steam sale and it was sort of in control until this last year with all these bundles. Now I have 100s of games on Steam alone and no hope to finish them :( Add Desura, Amazon, Origin, Gamersgate and I'm probably past the 500 game range...lol. Thankfully I don't pay much for them, but it is still a lot.