A few weeks ago, I submitted a run for Sonic 1 Green Hill Act 1, and just recently I got a response back saying it was rejected because the emulator was unidentifiable. Does anyone know what I can do next time to stop this from happening?

Might wanna ask the Sonic community what you can do, because their answer might vary from what someone here will say.

Reading the Game Rules (View rules -> Game Rules) will give you the answer.

Quivico, I checked the rules. Said nothing about emulators at all.

Copied directly from the game rules:

Emulator Rules (as of 8 August 2019)

The following unofficial emulators are allowed: Kega Fusion, Genesis Plus GX (standalone or through Retroarch.) Links to these emulators can be found in the Resources tab.

The Emulator used must be adequately identifiable at some point during the run (preferably at the start). The emulator must run at full speed.

Examples

Fusion (only 1 needed)

FPS Visible in the bottom of the window. Text in the bottom right either showing: Soft Reset Hard Reset x Startup (where x is either "Genesis", "MegaCD" or "Master System") Retroarch

Showing the Retroarch Menu that displays the Genesis Plus GX core and version in the bottom left. If not shown at the start of the run, please provide a timestamp in the run description of where this is shown.

For full game runs any use of a savestate/loadstate is not allowed.

For levels savestates may be used to return to a point before the transition to the level starts, but not during or after the run.

Mega SG

The Mega SG's main menu screen (the screen with the "Run Cartridge" option) must be shown before a run. The game must be visibly reset before a run. Submit Mega SG runs as "Sega Genesis" with the "Emulator" option ticked, and state that the submission uses the Analogue Mega Sg in the submission's description. For full game runs: The buffer options screen must be shown. If using the "Zero Delay" buffer option, RTA-TB time will be multiplied by 60/59.9228 to account for the frame rate difference.