What is the ruling on one who played games that contain polytheistic acts, then repented from them?

Playing with toys that contain polytheistic acts is impermissible, but it is not disbelief (kufr).

The important thing is that the repentance of a repentant person is accepted no matter what the sin, even if it was shirk (polytheism). For Allah forgives all sins for those who repent, as He, the Exalted, said: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'"

And the one who repents from a sin is like one who has no sin, and will not be punished for it in this world or in the Hereafter.