Several years ago, I had an idea about a very non-traditional Pokemon game, with a lot of mechanics that differ from most Pokemon fangames.
It involves an island that was basically trapped in its own time bubble, and recently reappeared in the modern era (right in the middle of a busy shipping route, which initially caused a bunch of chaos). So the world's leading professors and authorities launch a massive investigation into the island, though they quickly determine that the island appears to have been more or less untouched by human hands and technology until now. This causes the world's authorities to enact a rule that for the sake of preservation (and safety of the world, because who even knows what's there), not just anyone should be allowed in, so the nearest region (Hoenn) is given the responsibility of policing all traffic to the island. However, aerial investigations reveal that the island is actually larger than Hoenn itself - and somehow appears to be mysteriously growing and shrinking, with one observer describing islets flying in the sky, the next observer reporting rocky mountains in the same coordinates, and yet another reporting a vast desert below. The few known groups that have investigated the island on foot have either disappeared, or returned completely empty-handed. Those who have reported back mention that they did not encounter any Pokemon, but there were clear signs that they were present.
The main character(s) are a pair of older interns studying under a Professor, and the game would have very special rules compared to the traditional Pokemon game.