> Weird glitches. Flicker, or colors being wrong. Things running at the wrong speed. Things not rendering right. Sometimes the game crashes at certain spots. A

> Weird glitches. Flicker, or colors being wrong. Things running at the wrong speed. Things not rendering right. Sometimes the game crashes at certain spots. A lot of those were there in the original, especially flicker on NES, which was due to the sprite limits. That's actually something you can turn off in modern emulators, because it's an old and annoying hardware limit on the number of sprites per line. Some of the weird flicker/color glitches in the corners weren't visible or as noticeable on old CRT monitors, but they were still there as well because CRTs had rounded corners and some of the pixels there could be lost. If anything, emulators let you have an experience superior to the old days to filters, ways to bypass sprite limits, etc. And some games have been extensively patched by fans (Final Fantasy 4/6j in particular) or were only translated by fans, etc. That said, there are some differences in viewing things on a modern monitor vs. a CRT because of how the CRTs had more persistence due to how phosphors work and this could cause color bleed that's not there any longer.