The art is Stern's best effort ever. The playfield is very neat too, although it's inherently brutal. i understand fully why some people don't like it, but personally i'm a big fan of the shots, especially the far right ramp on the Pro, where you go backwards up the train ramp. it's a super tough shot and an original design idea.
The rules are its biggest problem. Way too linear. Also too many worthless modes -- including the "We Came We Saw" mini-wizard mode, which is bafflingly useless. Cross the Streams is worth way too much. the best play for novice and intermediate players in competition are to intentionally avoid starting a mode so you can go for the video mode on all three balls. that's dumb.
Also, it's way too hard to start a mode if you miss the skillshot. It's 3 or 4 risky shots just to LIGHT the modes. Speaking of which -- 6x playfield is a completely insane reward for merely making a skillshot.
and finally ... i don't understand why a bunch of side features (tobins and video mode at least) are disabled when you have a mode running. It creates a lot of confusion for players ("it said it just lit tobins but it's not lit!") plus it doesn't make any obvious sense. Not to mention, once you start a mode, it's pretty likely you'll keep rolling into the next mode upon completion of a mode -- meaning you'll always have a mode running for the rest of the game, meaning once you start a mode you can forget about ever seeing the tobins spirit guide or video mode features. It's a weird design choice.
heck, ideally, you should even be able to have modes from different ladders stacked as well.
anyway, i think there's a lot of room for improvement purely from a code standpoint.