I would be surprised if you could even tell a difference between 40 and 60 FPS. And if you can, just wait 5 minutes and you will forget about it.
I suggest you turn off FPS counter and just play the game.

NOLF series has some pretty clever weapons.
For example, a banana and an angry kitty bomb :D.

Bioshock is also for mac.

I think if there are going to be bosses there needs to be a decent number of them, and they shouldn't be optional....However, they also shouldn't use really cheap tactics so that it is no fun playing them and they just become a cumbersome task to get through the game.

For example: In Return to Castle Wolfenstein, there is only 3 or so Bosses (beat it last week, but still unsure of this number). Anyways, there are 7 levels and I found it really stupid how each level didn't have a boss, it was like they randomly chose which levels would have a boss.
And on top of that, the Tesla boss was really cheap IMO. If he sees you, you automatically get electrocuted or shot with a rocket. I had to resort to shooting at his arm from around the corner

Hmm, I would say my favorite "Underrated" game would be grim fandango

It has great puzzles with an interesting/fresh story.
And for being 12 years old the graphics are still playable IMO.

E.T. for Atari 2600LiftedHeadshot

There will always be people on BFBC2.

There are people on COD1!!! MOHAA!!! UT1!!!! And those games incredibly old.

So don't worry about people being on servers, because there will be people playing for the next 5 years at least.