My brother's recent post regarding Metroid Prime 3 reminded me of a problem with that game: despite the amount of effort it takes to collect all of the missile expansions and ship missile expansions, there is little real benefit from doing so. These items are presented as being rewards for the player overcoming difficult obstacles and puzzles, but they serve very little benefit for the player beyond a certain point.
Ship Missiles Expansions are the most obvious Fake Reward in Metroid Prime 3. As far as I can tell, they are completely useless. You only rarely even have the chance to use a Ship Missile attack in that game, and it is easy to replenish your missile supply between those rare occasions by just walking into the next room and shooting a crate. There isn't a single place in the game where getting even one Ship Missile Expansion will make a battle or puzzle easier.
Missile Expansions are slightly more useful than their larger cousins, but you will never need 255 missiles in the game. Unless you waste a lot of missiles against enemies resistant to them, you might never use more than 20 missiles between rechargs in the whole game. Having such large numbers of missiles was important in older 2D Metroid games, because enemies like Ridley, Mother Brain, Zeta Metroids, and the Queen Metroid all required a large stock of missiles for the fight to even be possible. In the original Metroid Prime, this was also the case for some fights, and the Beam-Missile Combo weapons provided another way of using large numbers of missiles at once, thus justifying the large number of Missile Expansions. However, Metroid Prime 3 does not have any fights that require a large number of missile hits (with boss battles being too dependant on the Hypermode gimmick), so there is no reason for the player to ever need a lot of missiles.
Spending the time and energy to earn something that is not useful is a frustrating experience for the player, and does not make the game any more fun. It is a pitfall that should be avoided in game design.