Insurgence/Zeta/Omnicron are all fantastic games, and I think that Z/O had some nice features that I wish were kept in Insurgence.
- Rocket Boots: I think this used to be in Insurgence, but was taken out. I thought that removing the need for HM slaves by introducing HM items was brilliant, but because of the Pikataxi’s limited locations, I still feel like I needed to carry around a Fly slave all the time (I’d very often want to fly somewhere while in the middle of a route). I really missed having the Rocket Boots.
- The Jukebox: It seems that this used to be in the Pokegear, but the Pokegear, and thus this, was taken out? The Jukebox was a really nice feature - makes the experience more enjoyable.
- The Mining Game: Pokepon is cool, but sometimes the complete lack of control leaves something to be desired. Although having an infinite source of free money, essentially, might be controversial, I thought the mining minigame was a nice feature.
- More accessible Nature changers (and to a lesser extent, IV Stones and Heart Scales: I know this is a controversial suggestion, because in one sense it makes building an optimized team easy and nearly invalidates the Day-Care Center, but I think a lot of people would like the ability to have control over these features (as opposed to praying with Pokepon). I understand that those who put in the time and effort should be rewarded, but I think having more accessible Nature changing opportunities is worth considering (especially for unbreedable Pokemon, such as Legendaries).
One idea I’ve had for this is to have Nature-changing NPCs scattered throughout the region, and they’d charge money per Nature change. The Nature changers who offer the “worse” Natures (Docile, Lax, etc.) would maybe only charge a few thousand dollars, and the “best” Nature changers (Jolly, Timid, Adamant, Modest) charging a ton of money (like 100K maybe) per Nature change.
And as I mentioned, to a lesser extent, my suggestion is to make sure that obtaining Heart Scales and IV Stones isn’t a cakewalk, but not a grueling task either.