Should the game owner be informed of the actual return if a specific amount was agreed upon but the actual return was greater, and what is the ruling on this ijara (leasing/hiring)?

It is permissible to rent out the game to others in two situations: The first is to act as an agent for the owner, renting it out on their behalf for a known and fixed fee, specified as a numerical value and not a percentage. In this case, you must hand over all proceeds to the owner. The second is for you to rent the game and then rent it out to others, provided that the sub-lessee is trustworthy with it and does not damage it, and that the usage is similar to your own usage or less harmful.

We also remind you that a Muslim should not make games their habit, but rather engage in beneficial activities. Permissible play should be for a short time and is forbidden if it involves gambling or leads to the neglect of duties.