For me it’s because I genuinely loved its jetpacks & the maps/gunplay/mechanics reminded me of bo2 but just added its own unique flavor. Plus as a freshman in high school, it was fun seeing everybody try to beat each other & for me at least it seemed the whole school genuinely loved bo3. 11 years later I still have nostalgia for this game & I’ll be forever grateful for the time I had with it. Zombies needs no explanation but Free run was underrated, sucks that it didn’t receive support afterwards though