It looked neat but I have the same problem as with music games like Guitar Hero etc - I'd rather continue programming on one of my many pet projects or practice playing actual guitar...
I may be missing out though - I wouldn't know because I actually never invested more than 30 minutes in any of those games (also bought TIS-100 last year, never actually played it once).
Incidentally - are there any music games (rhythm, composition, etc) that are similarly "hardcore" as a TIS-100 that anyone would recommend?
I finally might be giving TIS-100 another shot as it is Sunday and all :)