Banjo-Tooie is a sequel to the best-selling Rareware adventure game Banjo-Kazooie. Banjo-Tooie takes place two years after the main characters Banjo (a lazy bear) and Kazooie (an egotistical bitch of a red-crested breegull who is foul-mouthed, rude and proud of it!) defeat an evil fat witch named Gruntilda. Trapped under a boulder for all those years, her two evil sisters Mingella and Blobbelda come and rescue the already-skeletal Grunty. She and her sisters then fire a huge laser from their colossal digger and Banjo and Kazooie's house and in the process, one of their friends, Bottles the Mole, dies. Once again, Banjo & Kazooie go on an awesome epic quest to follow and kill Grunty and revive Bottles.
In Banjo Tooie, there is a lot more crude themes, humour and very subtle sexual references than its predecessor. this is the reason why although Banjo-Kazooie games look kiddish, they attract full-grown non-retarded adults as gamers. It is definitely an improvement to the first game, being longer (for the average person it takes 50 hours to get every single item), more sweet-looking worlds (like an underwater lagoon, a world in the clouds, a prehistoric world, and a two peaks with completely opposite climate), and generally a better audience.
I really like Banjo-Tooie for the N64. It easily makes my top ten any day.