I don't know man. Rules Rules Rules. It all boils down to rules. When you know the rules balls to bones, provided their decent, every pin is fun. I think Avatar is fun and challenging and I don't even know alot of the rules.I know almost noie for TRS and that's a big part of why I get bored easily. I've heard the rules are actually pretty decent. And, hand in hand, knowing the rules well probably means you've played the game more often, which is also mandatory for having a responsible opinion on the game. You can say it sucks after 5 plays, but should anyone actually respect that opinion? I think if either of these games had a second ramp (and/or third flipper) we'd be speaking differently about them.
Case in point: CSI. This game has solid rules. Not terribly exciting or deep, but well thought out and intuitive. Satisfying. The game also has cool toys and really tough shots and can be ruthlessly unforgiving. It's a great challenge. And when you're cruising through the thing with purpose and hitting your shots, it's totally addictive, and has some of the most hectic multi-ball action I've ever experienced. This game is one ramp and a couple tweaks away from rarefied air.