The game will be out on PS4 soon its going through the QA process, which is Sony making sure its up to par. An example of the kind of revisions:
Bug 11: When the towers attack the horde continuosly, the user will experience very poor frame rate.
the problem was with the bullets. Every time a gun was shot it created a collider to attract the nearby zombies. These attractors would eventually stack up leading to the problem.
I've fixed the bugs and am waiting back from the sony but this process takes a while as they will get back to me with more bugs to fix and so on. The game will be released as soon as most problems are fixed. It could be very soon or still a few weeks depending on how big the problems found are, and how quickly I can find a solution.
Thanks for the support! Stay tuned,