[Imp]

Avast has had a sandbox since the previous update, at least 6 months ago the update must have just set it to on.
If it is the only sandbox you have on your system it is possibly worth leaving it on as it makes your computer far more secure.
It makes your PC run more like a Mac or Linux PC in that everything it does not recognise is run in a "sandbox" so it will stop it if it attempts to do anything that could concievably affect your system on auto.
As the winsp games are not common it does not recognise them so treats them as a possible threat.

Guessing here because I have mine switched off as run a sandbox already but if you switch it to ask when something new is run it will ask you if its safe & if you want to remember the answer. If you say yes & remember it will consider it safe from then on & not bother to run it in the sandbox or ask you in the future.

So from a security point of view assuming it remembers your answer it will only run the sandbox & ask if its safe the first time you run something new it does not recognise so anything "new" on your system needs your permision to run the first time so cant be snuck on.
Note if it does not have a treat as installer option in the answers I would strongly recomend turnig it off if you are about to installl something or else it will ask you continually as each thing is installed most likely.