List of things I'd like
1) Change it up so you see Pokémon as you move.
They could put an algorithm in so it would randomly spawn so many Poke per KM so that way even people in the boonies would see stuff.
2) Fix the 1 HP Gym bug
3) Somehow rebalance Gyms.
It's either too easy to take over and then you stash one Poke there that's easily gonna fall. Or else it's a stacked gym of like 4 players and you can't beat them all in 1 go.
4) Implement a login queue
This way when servers do get overloaded it queues up people vs overloading and crashing shit. Plus the people who are in would have a stable experience.
5) Pick a server maintenance day and stick with it.
Pick a day like idk Wed morning, and have that be server maintenance time. Then stick with it. Doesn't even have to be every week, but keep the day and time. Then add a notification in app that says when server maintenance is. Blizzard already does this with Hearthstone on Tuesdays. Just copy that model.
6) Add in PvP battles but make them 2v2 only for people idk lvl 7 and above.
People are gonna rage at this idea, but hear me out. 2v2 makes it so you have to be more on the go and social. You'd need 4 people vs just 2. It also would keep people from cheesing XP on 1v1 battles if they owned say a phone and a tablet which they could create a second account on.
Plus locking it behind a level would give another carrot while ensuring people are slightly more leveled. Plus again it would cut down on dummy accounts just for XP.
7) Implement a CP value trading system
Make it so you can trade, but the CP value for each party has to fall within a certain range. This keeps it so people can just hook each other up nor can you cheat some kid out of their best while you give them some trash mob
8) Add in more Poke but at a steady pace
Don't just dump another gen in at once, but at the same time don't drip feed.
9) Fix the GPS walking egg bug(s)
10) Rebalance Poke Balls
This one like gyms is also all over the place. Some people live or work near like multiple Poke stops they can just spam for balls. Others have to travel far just for one stop.
Plus throwing balls is hit or miss, and AR seems to make it HARDER to throw and catch on average. Plus people with a ton of Poke Balls can catch all the trash mobs they want to power level while people skimpy on Poke Balls have to be more selective
Oh and get rid of the dumb curveball nonsense.
Following this up with 10 more things.
1. Fix the Capture Bug(s)
2. Add in a tutorial
The onboarding process in this game is non existent. It's crazy how big of an oversight this is.
3. Add in Shiny
I know there was one photo going around, but I've yet to see any real confirmation this is a thing yet.
4. Have evolved Poke give more candy
It's stupid an evolved Poke gives 1 candy like the base model. Even if it's something like base = 1, evolve = 2, 2nd evolve = 3 would be an upgrade.
5. Add in a way to slowly heal your Pokemon
6. Add in a home base
To piggy back on #5 add in a home base. Like you can select your house or apartment as home. Then when you are home and have the app on your Pokemon will slowly regen. Then you'd use the potions when you want to heal back up when your on the "go" so to speak.
It also would help delineate between home and go.
You could even make it a Poke Stop just for you. If they are worried about the items just make it so it's usable like once in the day and once at night. This would also help with the previous issue of Poke stops not being uniform throughout the player base and some people running out of Poke Balls so fast they are gonna quit.
7. Add in more character customization
They need more stuff here. Heck make it so you have more face, hair, body type, skin tones ect... for free then they could minimize clothing and backpacks if they want to.
8. Add in a friend's list
Also if they wanted to you could add in a toggle to show nearby friends on your map.
9. Slow down the pace of battles
Slow it down so it's not a tap fast fest. Make it so you really want to attack and dodge as well as pick your spot for special moves. This would also help in terms of bridging the CP gap as well used lower CP poke might be able to "out play" so to speak a higher level Poke at a gym.
10. Improve GPS accuracy
This is probably hard to do and very phone to phone dependant. Feels like at least for me the app is a lot of times a few seconds behind where I actually am though until I pause and it catches up.