Several people have pointed out that it isn't very interactive and "not a game". The interactivity portion is true, however the "not a game" isn't. The root of what makes a game is that there is some sort of competition. I agree that this definition allows games like "Press this button and hold it down as long as you can" to exist, but in the case of LU!, there is avenues of fun to be had. It's foremost 'competition' is basically seeing how long you will let it run. That is it. You can compete with your highscores as well. Past that, like Progess Quest, any other forms of competition are based on your own imagination.
I know that most gamers today are trigger finger twitchers, but this game does have its place. I added a tutorial the first time the game is played (and if you decide to turn it back on) to explain the game in full so as not to be deceptive about what exactly the game is at all, though, I know I am bound to receive some hate mail about it.
People are so finicky when it comes to spending $1. I have seen people blow $60 on a hastily released FPS, play for 20 minutes and uninstall because it is crap and not level the same amount of vitriol at those developers than I have seen on forums of XBLIG developed games. It confuses me as unlike the $60 FPS games out there, all XBLIG games have demos. You can actually try before you buy to find out if you like the game or if there are some problems with gameplay that irritate you or to figure out if you even like it. Guess what... you can even buy 60 of them for the same price as some FPS from a company that urinates on their developers to have them crank out Sequel Shooter 5: Herp of Derpers. Think about it this way, you could even blindly buy 60 of them and if even 1 give you 4 hours of enjoyment, you WIN! (4 hours comes from the average amount of time a person will play a AAA title released game.)
Anyhow, get out there, support the games you like regardless of who makes them. If you like Herp of Derpers, buy Herp of Derpers. But just go out and explore and try new things, you may find something wonderful that you enjoy.