I believe playing off of an online emulator and submitting runs like that is allowed, but I'm not 100% sure. It's up to the mods to decide.

I guess that it depends, but honestly, I don't think so, but like Mars said, it's up to mods.

I think for it to be allowed the website would have to use a core from one of the whitelisted emulators. Also I would NOT recommend running online emulator. Adware usually causes the game to slow down quite a bit. I've played online for practice during school and I'm pretty sure I've gotten down to ~45 fps. Therefore all your runs will be drastically slower than if you use any other platform. Bottom line: if you can get your hands on any other platform, such as a real emulator, it's going to help you out a lot.

A website emulator will likely never be allowed. I've seen them run slow and I've seen them run at like 200% speed for no real reason. We have plenty of other options for you to choose from to run the game.

Click the rules button on the leaderboard page. It's a whitelist of approved platforms and emulators. Basically if it's not on there, we probably won't accept it without sufficient data to prove otherwise.