The difficulty setting for this game can be changed at any time in the Prinny Base. The only change caused by the difficulty setting is the number of hits a Prinny can take before exploding: one or three. Despite the setting of three being listed as an option for "casual" gamers, the game is still very difficult. With either setting, you'll have one thousand Prinnies available to attempt to finish the game.
Except for the first tutorial stage and the later stages, the stages in this game can be played in any order. The 2 tutorials and the first six main stages are all available after the introduction and first tutorial.
The Prinnies have ten hours to retrieve the ingredients for Etna's Ultra Dessert. Each stage (not counting the tutorials) represents one hour of those ten. The first six stages vary in difficulty based on when they are played within the first six hours. It is generally recommended that more difficult stages are attempted first. The layout of individual stages as well as the boss that will be fought on that stage changes based on when it is played in the game.
When there are four hours remaining, the stages are opened upon completion of the previous stage (the seventh upon completion of the first six, the eighth upon completion of the seventh, etc.).
Over 580 Prinnies have been killed in producing this walkthrough to date.