Is it permissible to work for a video game company that produces both regular games and gambling games, provided one commits to working only on the regular games and refuses to participate in gambling games?

If your work in the company is limited to programming permissible games, and you will not participate in programming forbidden games, then your work is permissible. It is advisable to seek work in a field more beneficial to people, especially in Muslim countries, as the Ummah is in need of trustworthy specialists in modern technical fields to be an aid in acquiring means of strength and honor.