Disagree. It came in with a lot of hype from the game makers and magazines, then most magazines gave it decent scores, which is what the game deserves IMHO.
Bubsy wasn't great, it wasn't bad... it was just OK and received way too much hype for such a non-stellar platformer. I expected the next big thing, but in the end, it was only slightly above average. The controls were suspect to say the least. Sans those who vehemently slam the game, I think it's rated about right in the gaming community. Most people see it as nothing great but nothing horrible, either. At least, that's my general perception. I think that's about right for Bubsy.
Underrated is SNES B.O.B. There goes one funky, weird and strangely fascinating action shooter. Not great, but it really got overlooked and is a fine game that might occupy you for a solid week or two