Maybe there should be a minimum playtime to review or something? idunno how that would work with non-webgl games tho.
I wouldn't be surprised if they have such as system on itch.io since they host so many jams. In a database (which this whole jam is in essence) a simple cluster analysis (common method to determine insurance fraud) would uncover every suspicious transaction (in our case rating) instantly. I simply don't know if such a tool is available to the hosts, since I never hosted a jam myself and have no clue about the back end.
But I would never implement a hard timer. Not only would this give you tons of false positives, it is just going to make some people pissed.
Well what can I say, accept that I am that guy that reads the license agreement in full before installing the software. I try to improve, I really do.
Since I have nothing better to do and I want to improve my c# I will actually try to make a monitoring API. A rudimentary one, but we don't need a lot.
I'm a bit envious of you as I just read the headers of TOS sometimes when installing application in my PC. If you are focused on self improvement I think you will definitely have a lot of success in your lifetime, maybe you already do.
If you manage to make that monitoring API, I think itch.io will definitely take an interest and it will help to make the game jams alot better experience for everyone. :D