the characters (and everything else) being made of Legos is very well done, and gives everything a look that reminds many of us of our childhood, thus helping the game atmosphere to be fun in a child-like gleeful sort of way.
The gameplay is very good, very responsive controls, and there is a lot off-screen in any shot to be discovered (like Super Mario Galaxy).
Unlocking new characters to play and new items is fairly easy, while the objectives for each “scene” grow harder and harder as you progress thru the story. There are, btw, A LOT of unlockable things/people in each game (I’ve played thru the Star Wars and Indiana Jones games, FTR).
It’s hard to describe exactly, but the games are a lot of fun and offer a fair amount of replay value, since you are unlikely to unlock everything the first time thru. Also, failing and retrying levels (scenes) isn’t heartbreaking like in some games, it’s just a chance to have fun again.
Personally, I thought the IJ game was slightly better than the SW game, as if the makers had gotten better at what they were doing. So I have hopes that Batman is even better still.
I should prolly mention that I have only played these on the Wii and Xbox. I haven’t tried the DS versions, so I don’t know if scaling it all down hurts the game significantly or not. Yet.