hi! i'm unable to install the do to an "no manager to install unknown" error. is there something obvious i'm doing wrong? any help appreciated
There is no installer. You just open the .nes file in an NES emulator (I recommend https://www.mesen.ca/ or https://fceux.com/web/download.html).
Does that help? If not, please give some more details on what exactly you are trying to do (maybe include some pictures).