Shares of Santa Monica-based Activision took a 5 percent tumble today, despite the company holding video-game rights to "Spider-Man 3." How exactly can that happen? Easy - terrible product reviews. The Spider-Man game designed for the PlayStation2 platform scored a 55 percent ranking by Gamesranking.com, which is considered pretty bad. Some folks downplayed the poor reviews and attributed the lower stock price to a nearly year-long runup in anticipation of the SM3 opening. Activision also has game versions of "Shrek the Third" and "Transformers." Activision closed at $20.17.