Despite originally being written off as a simple kids game (thanks to Disney's involvement in the title), Kingdom Hearts has a quirky story which is surprisingly deep, dealing with the idea of friendship and inner-belief in a powerful manner. Darkside is the first boss of the game; it emerges from Sora's shadow during his Awakening and serves as a test for the future Keyblade wielder. Darkside is significantly bigger than Sora and the dark, atmospheric arena it is fought in creates an intimate setting which sticks in the mind. On top of that, the fight gives players a good chance to learn the game's mechanics. Parrying Darkside is really easy and it's a great way to learn the timings needed to get consistent with the skill. Darkside pops up throughout the rest of the game (and, as a matter of fact, the series) with a similar moveset each time, making the first encounter all the more important.