I downloaded a game that supports mac os, but for some reason it wont open 'This application cannot run." I am super confused. I have the right system, maybe I downloaded from the wrong browser? I have opera.
Your best bet is to ask the game's creator, they're in the best position to offer support.
I've come across this issue a lot on here, unfortunately macOS games are either not tested properly (if at all) and have bad support.
The best thing to do would be contact the game developers.