Instructions
Start a night mission. During day missions, you get Moon Medals. Sun Medals only appear at night.
Progress through the level. Periodically, the game will prompt you with an objective, such as "Dash and Jump" or "Let Fly the Were-Hammer." These objectives have time limits. Complete them before the time is up to earn a Sun Medal.
Grab as many rings as possible. At the end of each level, the game assigns you a rank. The more rings you gather, the higher your rank will be.
Rack up attack combos when you fight enemies. Perform combos by alternating swings between left and right. Getting large combos further improves your rank.
Complete the level within its time limit. When you're done, the game presents you with a performance report. If you collected all the rings, executed combo attacks and completed all of the objectives within their allotted time, you will receive S-Rank and three bonus Sun Medals.