I'd say all 3 KME games play completely differently, but there are similarities. As AIQ is only developing code, it's hard to compare rule sets right now.

IMdn and JP2 both have 6 way untimed combos, 11 tomb treasures and 11 Fossils, multiple main MBs plus easily accessible mode MB, no VUKs - preferring up-posts to trap the ball.

IMdn is much more of a slog than JP2, especially if you fail to collect a SS from a mode, or LV2 Eddie from a MB. Getting to Cyborg or later modes requires numerous ramp shots - which does feel repetitive.
JP2 is never a slog, there are 3 main aims/wizard modes to progress towards, all of which are somewhat independent.

To me the standout/innovative features from his first 2 games are:
IMdn:
Bullseye 'bash' target with additional reward for accuracy.
The number of different skill shots
JP2:
4 ramps which can be combo'd
TRex Holding and throwing ball

I couldn't get enough of playing IMdn and JP2 the first time I saw them on site, so much so they (along with AIQ) are my only NIB purchases to date.

AIQ:
The Iron Man lock tower is brilliant
The Gauntlet ramp, I cannot think of another major shot, let alone ramp that is accessible from all 3 flippers on any machine.

I think what KME brings to the table when designing a game and rules, is knowing what works, and more importantly doesn't work, in tournament games. There isn't an overriding strategy that allows you to ignore huge parts of the game if you want maximise your score or reach the wizard modes. Hitting the same/safe shot over and over doesn't reward you as much as other games do. Almost every game I can think of when I have watched or played in tournaments the players play the same way and ignore parts of the game.

Any game by any designer is going to have similarities, especially when using the exact same template for the bottom 1/3 of the playfield and the same playfield dimensions. Any game that strays from the standard outlane/inlane (x2), slingshot, flippers, slingshot, inlane outlane, shooter lane generally gets a bad press.

It would be nice to see more variety, perhaps gaining additional playfield area at the bottom by having the ball enter the playfield from the top, or via a 1 way gate on the right outlane. It would change the overall geometry of the game, perhaps freeing up different ideas, or resulting in layouts that don't 'work/flow'? Who knows.
Have a game without inlanes, or even without outlanes! Like so many of the older games.

However, even sticking to the traditional bottom 1/3 layout KMEs 3 games so far feel fresh and very different to what we have seen recently, but more importantly they are fun to play, great in competition, easy to understand the basics for a novice as well as having the depth of strategy to keep better players more engaged at home.

Overall I love KMEs first 3 games, as I do other games from other designers, DP, BM66 & TWD are also favourites.

If you don't like his games, don't play/buy them, but don't try and force your views as to how he should change his designs, there are plenty of people out there who like them just as they are.