I read they do nothing, just cheaper to make.  But I also read testimony that the ADE versions run better somehow.

Either way, there should be some differences in the games regardless, like level layout or something.  I'm not quite sure.

That was the clame, that graphics were supposed to be better.  I think that is impossible cause the NES can only handle 8 bit.  The main reason for it was money.  Inside every NES cart it has 2-3 chips usually.  The Aladdin Deck Enhancer had 1 of those chips inside it, so there carts didn't have to both from my understanding.  Plus the carts are smallers using less plastic, plus a smaller label, less ink.  The ADE itself was being used to play the game and making it chaper to make future game (never happened, they went bust first).  This was a great idea cause from what I have seen there price point on there games was only going to be like 19.99 or something compared to the 39.99 or 49.99 of regular NES games.  They hope to make up for price with volume of sales.  Unfortunatly they never had the chance and coudln't pay for the ADE.

The Aladdin Deck Enhancer's hardware is no better than a particular game's standalone-cartridge hardware.  The only game that has any appreciable difference from its cartridge version is The Fantastic Adventures of Dizzy.  In that game, Dizzy walks faster and there are more stars to collect.  On the other hand, Dizzy the Adventurer was only released in the NTSC countries as an Aladdin cart. 

I strongly disagree with the previous poster that the Aladdin games are crap.  Camerica's games in general had a consistently high level of quality, even though many were ports of games for the ZX Spectrum, Commodore 64 and the Commodore Amiga.

Quattro Adventure does suck indeed, but there's a sequel to Linus Spacehead (a game in that collection) called "Linus Spacehead's Cosmic Crusade", which is MUCH better than the original, but it's not a masterpiece by any means.