I'm indirectly involved / hear about a project that buys up old feature phones, mainly from Japan, to try and find ones that have data for old imode games on them, notably a FFVII spinoff called Before Crisis. It's difficult because they would release the game in separate data packs, the idea being people can remove data packs for parts of the game they already played to save space (also a feature on modern smartphone games). But since the servers are long gone, they need to find phones with the data on them to extract it.

But they've made really good progress in recent years, to the point that the game is now playable. Not sure if it's complete, but it's playable. See e.g. https://www.oldschoolgamermagazine.com/work-begins-on-restor... for info.