There is minor trainer customization (appearance and starting town) and you can tackle all 16 gyms in any order. Gym leaders' levels and team compositions will scale up based on the number of badges you have. After you've conquered them all, you can re-battle them at whatever 'badge scale' you wish, to take on their strongest or weakest teams. You need a total of 8 badges (any 8) to challenge the Elite Four.
Version 2.5.8 (Label art may vary)
All 251 Pokemon made obtainable
7 different male and female trainer sprites to choose from, with basic color customization
28 different selectable starter Pokemon
Restoration of Kanto dungeons (Safari Zone, Cerulean Cave, Seafoam Islands, etc.)
Following-Pokemon, and unique menu sprites for each Pokemon species
Running shoes, and fast-travel options
Dedicated NPC for trade-back evolution
Pokemon Crystal Clear v2.5.8 (GBC)
This game is super fun when compared to actual Crystal. I’m 4 badges in now and love the open world free roam layout with no obstacles to it. Runs pretty smooth playing on my SP and I was lucky enough to get a shiny Seel as my starter when I was resetting to try to get a girl!
Runs awesome and the cart looks really cool!
In the specific version of the game that this cartridge holds, it doesn't let you choose between Pallet Town or New Bark Town, it lets you choose to start in literally any town or city in the game. (For best start I recommend starting in Goldenrod as you can get two gift Pokémon there. Eevee at Bill's house, and Kenya the Spearow from the north checkpoint in Goldenrod. Both of which are shiny huntable.)
Super fast shipping awesome game!!!