I wouldn't say stupid, but certainly goofy as hell, and purposefully so. I thought it was great, and I think it was a great swan song as one of the last sci-fi movies that I can think of that didn't over CGI everything. Sure, it had a healthy dose of CG, but you just don't see many movies that use puppets or full costumes for aliens anymore. It's all computer generated in some way.
On a side note, my friends still reference that movie...if somebody owes someone else some money, or is settling up a bar bill, it is not unheard of to hear "GIMME THE CASH!"