Although Banjo-Kazooie: Grunty's Revenge is noteworthy for being the first of Rare's games in more than a decade to be published by a company other than Rare or Nintendo, there isn't much else that distinguishes it from any of the other dozen or so top-down action games that are already available for the Game Boy Advance. Rare went with its usual formula, fashioning a solid-playing game with high production values and a lopsided emphasis on item collecting. Ultimately, though, while Banjo and Kazooie have a healthy variety of moves and attacks, the short nature of the quest combined with the almost obsessive-compulsive focus on grabbing items means that players will hardly get a chance to enjoy what the characters can do.
Banjo stands next to a single musical note, one of 600 you'll collect throughout the game.
The events in Grunty's Revenge take place just after the conclusion of the original Banjo-Kazooie for the Nintendo 64. Banjo and Kazooie had just left the evil witch Gruntilda buried under a 10-ton boulder, but unbeknownst to the pair, an inventor named Klungo came along and transferred her spirit into one of his robotic inventions. Gruntilda's new scheme to conquer the world involves traveling back in time. With the help of the good witch doctor, Mumbo Jumbo, however, the heroic duo has followed her into the past and intends to thwart her plans once again. All throughout the game, you will encounter younger versions of characters that appeared in the Nintendo 64 Banjo-Kazooie games.
Banjo and Kazooie are separate characters, but they work together as a team. Banjo is a bear and Kazooie is a bird that rides around in Banjo's backpack. Together, they have a large repertoire of moves, which the game does a good job of introducing gradually. At the beginning of the game, Kazooie is hidden away, and all Banjo can do is walk, jump, crouch, and swing his backpack at enemies. Collecting musical notes allows you to purchase additional moves from Bozzeye the mole, but with Kazooie out of the picture, the only three abilities he'll give you are a tackle technique, the ability to climb ladders, and the know-how to swim and dive underwater. Once you find Kazooie, you can add seven more skills to the duo's repertoire. These include a high jump, the ability to fly short distances, temporary invincibility, the ability to use Kazooie's beak to jab enemies, the capability to carry and shoot a variety of eggs, and a pile-driver move that allows you to shatter cracked areas of the ground. The final skill you can acquire allows Banjo and Kazooie to switch roles, with Kazooie carrying Banjo on her back. Even though you can't attack or defend yourself while controlling Kazooie, this is a useful technique since it allows the pair to move faster and to climb slippery hills that Banjo is too heavy to scale.
Besides the duo's standard array of skills, there are times when you can transform Banjo into an entirely different creature with its own specific abilities. Although time travel doesn't come into play as anything more than a plot device, it did give the programmers a good excuse to make the transformations in Grunty's Revenge different from those found in the Nintendo 64 Banjo games. Instead of a termite, crocodile, walrus, or pumpkin, the younger version of Mumbo Jumbo in this game can turn Banjo into a mouse, squid, candle, or tank. Each transformation has its pros and cons. In mouse form, for example, Banjo can enter tiny openings that he isn't able to fit through as a bear; but as a mouse, he also can't fight back when enemies attack. Likewise, the tank is a monster against steel doors and the majority of enemies, but it sinks like a stone if you fall into water.