Great story. I can't quite understand how people can complain about the game being too easy. On a personal level, a game being good isn't about it being difficult or easy, it's about it being fun - and this is a fun game. It's got all of the best elements of the adventure genre being done right. The fact that it's the first game in 3D to fully retain all of the charm and playability of classic point-and-click 2D adventures is just icing on the cake. The fact that gameplay is improved due to the new and elegant interface (proof that we never really needed all those verbs in the first place) is icing on the icing. Diabetes never tasted so good.

On a more pragmatic level, let's look at a few simple facts:
1.) The adventure genre is a niche market so, by definition, adventure games currently appeal to a small percentage of the game-buying public. (Hopefully that is changing even as we speak, though.)
2.) Extremely difficult adventure games appeal to a niche of the adventure niche. In other words, if one were to release such a title, it would appeal only to a small percentage of an already small percentage.

If I had a pie chart, this might be more effective...especially if it was a really tasty pie. Who wants to gaze longlingly upon a delicious chocolate creme pie only to be served the tiniest sliver of an already depressingly small slice? That person would walk away hungry and, removing the metaphor, that game company walk away out of money and out of business.

Let them increase the difficulty as the episodes progress, but let us hope that the puzzles never reach the bizarre levels that so many current adventure games have devolved to. Fill the game with more content and more things to see and do and laugh at, not simply more and more obscure puzzles with increasingly nonsensical solutions that do nothing more to add value to the game than providing a very few people the fleeting and smug satisfaction of having endured clicking on enough combinations of enough items until they stumble upon the correct solution. Everyone else will just skip that frustration, go to Gamefaqs, then complain about how the game was too short.

My philosophy is to keep the player always progressing. You can slow the progression here and there if it serves the best interests of the game, but never grind things to a halt with frustratingly difficult puzzles. At best, they add nothing to a game for the overwhelming majority of players and, at worst, they hurt the game by producing the opposite effect of what's intended (extending playtime) because a FAQ is only a web browser away.

In conclusion, this first episode of Sam and Max is absolutely perfect. More, please.