All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
Games are prohibited or permitted according to their content, if they didn’t involve prohibited matters or actions then they are permissible, in this regard Al-Imam Moslim (May Allah have mercy on his soul) has pointed out games in his Sahih under the category of: ”The Permissibility of games which don’t involve a sinful act during Aid.”. In addition, playing or helping in games which are based on gambling and the like or the ones which violate Islamic creed are prohibited.
Therefore, opening PS store is permissible so long as the games don't involve any evil acts nor to help or acknowledge the ones with evil contents such as: Gambling games and the ones which include matters that contradict or violate with the teaching of Islam.
On the other hand, opening PS store is impermissible if aforementioned evil acts or some of them were included, because this is a sin and giving a hand in achieving it is prohibited for Allah, The Exalted Said (What means): ” Help ye one another in righteousness and piety, but help ye not one another in sin and rancour: fear Allah. for Allah is strict in punishment.” [Al-Maidah/2]. And Allah knows best.