Ahh, I see, so by lightweight you actually meant in terms of the workload? That's just elegant, there. If you're a developer capable of adding a lot of gameplay with little work and still have it be fun, varied, and challenging, that's pretty darn elegant. All of those game modes were really what I was looking at when I referred to all of the content. I remember Tidalis being one of those games that was particularly hard to learn for me, I remember the modes and stuff, but I never got good enough to get into the campaign or puzzles. There's a point where the campaign just like locks you out of doing anything until you're like MLG level at match-3-with-a-twist.
But yeah, the thing I guess is that the gamemodes didn't have all of the complexity that monsters do. Each monster has a lot of art assets, careful tuning of animations and attacks, don't even mention fighting with balance. Game modes are much more abstract. The blocks themselves don't really attack either. They're more like rules that move around and flow with the gameplay. Or, in the case of turning on the items, basically convert the game into Super Smash Bros Brawl.
Regardless, that kind of stuff is really cool, and adding that sort of element is something that I would want to do in any game I had a part of. I'm referring to some more abstract things that change the way that the game works, like the game modes in Tidalis. I only particularly see advantages in doing that. Is there any real disadvantage to adding replay value in that way? I guess, maybe for a team that isn't as great at game design, it might end up being harder.