Every game on this site is checked before it goes up and re-checked afterwards. Here is exactly what that means, including the limits.
First, the game itself loads. Second, its host allows it to be shown inside another site; some games refuse, and those cannot work here at all. Third, its picture loads, so there are no blank cards.
A game that fails any of the three does not go up.
Every game is also opened in a real browser three times: sized and behaving like a phone, like a tablet and like a laptop. We check that it actually draws the game on screen, not just an empty page.
Games whose controls need a keyboard are marked on their page, so nobody on a phone is left wondering why nothing works.
A game that loads is not the same as a game that is fun on every device. Automatic testing cannot play through every level or try every control. If a game is broken for you, the contact form reaches us and we check it by hand.
Games can break at the developer’s end after they go up. The whole catalogue is re-tested automatically every week, and anything that stops working is flagged and taken down.