Before developing their idea to make the excellent game Celeste, Maddy Thorson and Noel Berry had first made a version on the fantasy console Pico-8 now called Celeste Classic, and playable for free here.
I found the celeste classic port for GBA made by JeffRuLz and as I love this game and this console I wanted to have a real cartridge.
So I used a Pokemon Sapphire repro that I reflashed with my sanni reader to put the celeste classic rom and made a label with holographic sticker paper.
I thought that it could interest other people so I made several that I put on sale on my Etsy store
The port was made by JeffRuLz :
https://github.com/JeffRuLz/Celeste-Classic-GBA
The original game is developed by Maddy Thorson and Noel Berry :
https://www.lexaloffle.com/bbs/?tid=2145
The Sanni Reader I used to reflash repros :
https://github.com/sanni/cartreader