It's been out on steam for ages now, so I presume someone must have played it ?
I thought it was freakin' awesome. I really enjoyed JC1, but there were some massive problems with it, such as the Copy Pasta environment and boring combat.
JC2 has fixed these and still retains all the cool things about JC1, some of my favourites being the Mission Impossible style stunts that you can pull off, the massive map and pretty much everything else.
And also, the graphics are above and beyond the call of duty, the environments are face melting even from thousands of metres up in the air.
Totally buying this at some point, it's just a shame there's no MP, a GTA4 style Co-op would rule.