Honestly, fifa is a great game. Although there needs to be a lot of new improvements.
1. Rewards - People that constantly play the game deserve a lot more than people that don't. Something as simple as a 'daily reward chart'. And maybe it could result in a 100k pack after 5 days. Winning divisions should also get much much better rewards.
2. Packs - The pack weight is actually terrible, it needs to improve so much.
3. Challenges - Why are there not challenges? This is the simplest idea, yet its not in fifa.
1.Create a decent Edit Mode, so we can edit (at least, offline) the unlicensed team's kits and some players's faces, hair etc.;
2.Create a "Panic Button", for those messy-clumsy times you desperately wants somebody to kick the ball as hard and as fast as possible, instead of just stand looking at it (Attack and Defense);
3.Be able to properly adjust your team before online friendlies (instead of being caught in the middle of it and lose all your progress) and be able to use customized sliders (approved by both players) when playing with friends;
4.Bring back the training menu where we can practice free kicks, penalties, corners and etc. the way we want (instead of the pre-defined and boring on skill games menu);
5.Improve goalkeepers physics, especially that moments when they run to catch the ball and just passes through all the players in front of them (like if they were ghosts!). A lot of those moments where they dive at players's feet would be penalties (specially those ones where the attacker has his back turned to the GK, but still, the GK passes through them and catches the ball) but nothing ever happens;
6.Make the players a little more aware of tactics and what's happening in the game, and eliminate the "auto-tackle" feature. Awareness is a huge problem in Fifa 16;
7.Create a team from scratch in Career Mode;
8.Create your own kit in FUT;
9.Online tourneys with random teams, based on your skills to even things out;
10.Some new CPU engine that actually plays using DIFFERENT tactics instead of the same tactic ALL THE TIME, passing the ball as Pep Guardiola's Barcelona;
11.Some feature that allows us to propperly see the rival team and them try to create some tactics to defeat those players who always do the same play over and over again (an easier way to set man-marking would be nice to stop pace/dribble abusers).