What is the ruling on contributing to the development of a computer game that is sometimes played during prayer times, and does the game developer bear a sin if people play it during prayer times?

It is not permissible for you to install the game in the shop if you know or strongly believe that the shop owner does not close his shop at prayer times, or that the game will distract players from prayers, or if it contains something forbidden, such as music. This is based on the Almighty's saying: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression" (Quran 5:2), and on the Prophet's (peace be upon him) saying: "Whoever introduces a bad practice in Islam, upon him is its sin and the sin of whoever acts upon it after him, without any decrease in their sins."