Kresnik on 31 October 2016
http://blog.us.playstation.com/2016/10/31/fight-for-survival-in-zero-escape-the-nonary-games-out-next-year-on-ps4-ps-vita/
Aksys' way of handling 999 on Vita is... weird. But anyway, it's coming in 2017 (bundled with VLR for some reason)