Difficulty indicates how hard a playthrough of the game is. Different difficulties affect how much health bosses have and the number of save points per world. The easiest difficulty affects how quickly you can fire projectiles and the difficulty of certain platforming sections. There are 4 difficulties to pick from.
EZ-mode - As the name suggests, this is the easiest difficulty. Nearly every screen throughout the game (excluding boss screens) has between 1 and 3 save points, bosses wear giant pink bowties and only have 50% their standard health, rapid fire is enabled, and most platforming sections will include little pink heart platforms to help you through the level. Note that you can't truly become the boshy by completing the game on this difficulty. In addition to the bosses, all Default Characters (except Boshy) have pink bowties, but in much smaller form.
Totally Average-mode - This is the "normal" difficulty. There will be between 0 and 2 save points per screen, and bosses have 100% of their health. From this difficulty on, rapid fire is disabled, the heart platforms vanish, and bosses no longer wear bowties. You must play on this difficulty or higher to unlock Ryu, Solgryn, and Dark Boshy as playable characters.
Hardon-mode - This is the standard difficulty and the second to hardest difficulty. You may progress through 1 or 2 screens in a row without finding any save points, and bosses also have 100% health. You must play on this difficulty to unlock Sonic as a playable character.
You're Gonna Rage-mode - This is the hardest difficulty. There are only 2 save points per world, one at the start and the other at the end (with the exceptions of world 8, where 7 save points are required to obtain a CD item, and world 11, where 2 save points are required to make your way over a pit), and bosses have 200% health.
- Even though it is the hardest difficulty, beating the game on You're Gonna Rage-mode does not unlock any exclusive prizes. Instead, you unlock the same rewards as Totally Average-mode. This means you cannot get Sonic by playing in this difficulty.
- You're Gonna Rage-mode used to be called You're Gonna Get Raped-mode. This change was made because some people found the old name offensive.