You get a choice of like 18 different playable trainer skins and 80+ different starters
Then you learn that you can have all 6 of your party pokemon following you around on the overworld
Then you got the fact that you encounter pokemon via pokemon walking around in the grass, including visibly distinct shinies.
Oh and it has the full 1000+whatever pokedex so every different route has 20 pokemon walking around so as someone trying a Nuzlocke I'm just standing there struggling to decide which one to take
Oh and also since it's a romhack so I'm playing it on my 3DS
GBA era romhackers are something else
Download either the installer or the portable directory of mGBA here
Download this .gba file (it is already "patched" and ready to play) here
Run mGBA and do File > Open ROM and open the .gba file with it and you should be good to go