They should retconn Mr Mime already. It's been far too long.
What, gender-wise? You surely know its name in Japanese isn't specifically masculine.
since theres no death in pokemon.
Hmmm not quite.
Oh I am aware it isn't called Mr.Mime, and there's been death yes, but not in game play terms. I'd say Cubone evolves from a Kanga baby if its mom faints in battle while its in the party, but then it cant get the skull unless that fainted kanga disappears, like an opposite ninjask evo where u get shedninja and ninjask, and the adult 'dies' but that wont work. If they just left the death as an assumption and let u capture both baby kanga and cubones, where adult kangas and marowaks coexist, it can just be a subtle thing.
Also I think equipment on pokemon being visible be awesome. Everyone would be sporting Black Glasses.
Multi-type moves New Types Abandoning Turn-Based Grimdark story (slightly darker would be fine, the levels most want to take it to is not.) Sextuple battles (Sextuple rotation would be cool, though) an area that gets worse in real-time, making it so you only have so many IRL days to beat the game (oh, wait, that's not fan-based)
Also Kang pre-evo is long over do and it's pretty much been put into every fan made game ever and it works. It doesnt NEED to evolve into cubone, since theres no death in pokemon, it can just be mentioned in dex entries like it always has. Just put wild kang babies and cubones in the same area with adult kangas and marowaks and it gets the point across without needing to kill pokemon off. Heck, have an NPC give u a cubone and tell u its mother was 'lost' during a marowak/kangas territory battle to solidfy the point.
A bad fan idea I've heard: that Cubone and Kangaskhan are or ever should have been related.
Things like new types are not bad fan ideas; they're unnecessary fan ideas. Unnecessary =/= bad. (Well, stupid types are bad ideas, but I'm talking things like "Red type" and "Monkey type" and "Firefighting type"; you only think Light is a "stupid type" because it doesn't already exist in Pokemon. I do not care whether or not they add a Light type so long as they are smart with how they modify the type chart to accommodate.)
Creator of Jay's Journey (see quote!) "It's not ten years old! Therefore, it sucks!" - Nostalgia whores everywhere