It's definitely possible to run something like hq3x in real time, and many emulators support that, though I'm not sure if RetroPie specifically makes it easy to

It's definitely possible to run something like hq3x in real time, and many emulators support that, though I'm not sure if RetroPie specifically makes it easy to configure that stuff. Though I'd argue that algorithmically smoothing out low res art frequently makes it look worse than the source material.