Mode Status during selection - this is an absolute must. I should be able to see how many shots are remaining on a mode before selecting it to decide if I want to try and beat it or move on and get closer to the extra all and the first wizard mode.
Upgrade/Crank it Up - many of the modes reduce the number of shots to just the two ramps or two orbits. More unique rules for hitting this would be nice. Right now I avoid it intentionally on some modes because it makes the mode completion more difficult.
Mini-wizard modes - my biggest beef with Aerosmith is it basically just has the two wizard modes - one for starting all the modes, and the other for when you complete it. this game needs some interim mini wizard modes to go after that make you feel like you got somewhere special on the game without having to get to one of those big wizard modes. i.e. DTR in LOTR, or Light Saber Duel or Escape Boba Fett in SW, HOTK in GOT, etc.
Groot - we absolutely need him to "speak" to us. I know it's gimicky, but watching that jaw move while hearing "I am Groot" will be cool every time he does it.
Rocket - that shot is crazy tight and super risky. Spelling rocket should carry over from ball to ball and not reset on the next ball.
Mode Champions - it would be cool if each mode had a champion you could put your initials in for. gives home and on location players one more reason to try and dig deeper and get more points on a specific mode.
Groot MB - it would be nice if the logic followed similar to Aerosmith in allowing the user to choose when to go for MB or risk delaying and trying to lock more for more points. The MB is too easy to get right now, I'd prefer to see a few more shots required, or maybe some other mechanic to light groot to open his mouth for locks and then build up. Option to have a 2 ball MB if wanted, or go for 3, or for 4 first time through. Subsequent times through could require more effort to light the lock in the first place, similar to what is programmed today.
Super skill shot - really, 1 million for hitting a super tough shot? this should be MUCH more. and grow higher every time. there should be a super skill shot champion and extra award/mode if you complete all 3 of the super skill shots (orb, right ramp, and right orbit). how cool would that be? tie it into Yondu's arrow or something in light of the fast, precise nature of the shot.
Spelling Guardians - i believe this lights mystery, does maybe something else? here is another opportunity to add a fun hurry up, etc. with some cool lighting effects, etc. maybe completing enough hurry ups starts a special mini-wizard mode. something new and fresh that you don't see every time, but also something that can be reasonably achieved.
Songs - ditto on what O-din said. I nit picked this previously and didn't see a good way for these songs to be introduced without getting old - i take that back, random selection of 6 to 8 tracks playing while you are in between modes would be a good way to use those licenses without making them too repetitive.
End of ball character shots - another opportunity for a hurry up or some other substantial reward - if I hit every shot on the playfield during one ball it would be cool if that started a hurry up or built up towards a mini-wizard mode or something. one more layer to add to this game.
Other than the obvious additions of more music, callouts, video, and audio, I think the base rule set is solid and fun. These other items could take it over the top and add that lasting value to a home location and provide more on location incentive to play.
As an owner of a Pro, I find the game really fun to play but question it's lasting ability. Seeing some of these ideas implemented would go a long way in changing that to its "bolted to the floor." The artwork, music (in and out of modes), video clips (I don't care what people say about them feeling "disjointed," I like the ones I've seen) and shots are really well done along with a top theme of mine.