It plays perfectly on my 5s. The only problem is commentary (it just randomly says "The Nets!" Every once in awhile, that's it) and the battery suck. As long as I play plugged in, it's great!
It isn't really 3gb. With app shaving this clocks in at 1.6 on my 5s then grows to 2.2 with game play.
Sorry for everyone having the crashes. 6s Plus works fantastic, I played for three hours on MyCareer last night. I actually prefer no voice-acting in between games. Hopefully they will stabilize it for older devices. I don't feel the need to buy a console 2k game anytime soon.
Base on app description you need ios9 to play. Not sure if it's me having perhaps low tolerance for frame rate but it bugs me a lot on iPhone 6.It is marginally better than nba2k15 but nowhere near stable/smooth. On a separate note, few games (eg fifa16) have worse frame rate on iphone6 since ios9 upgrade...).
This is why big publishers cheat us. They have not fixed bioshock but people are still buying this. Capcom ea gamesoft and 2k won't stop doing what they do because they know we will still buy!