for those that don't know, emulators allow you to play handheld/console games on devices besides the devices/platforms they were designed or released for. in other words you can play nintendo ds games on your phone, or ps2 games on your pc, etc. there's lots of possible, feasible variables [can your calculator/ipod run doom? my ipod does], and some are a work in progress.
in addition to that, some emulators have a feature that allows you to unlock game achievements [think ps3/xbox 360 and beyond and some steam games are built to do]. i'm most familiar with retroachievements [my profile here]. just put your username/password into the emulator and you're all set.
if you're new/familiar with this feel free to add me 😌 if you have questions on setup or anything i'll help the best/quickest i can
edit: retroarch is afaik the most popular one stop shop for emulation on pc, more streamlined setup for a good amount of platforms you may happen to have/want to play games via emulation but not all
