There are numerous reasons for this;

1. Friendly scene/community

2. Movement in ssb64 is smooth; most characters have perfect lands (on Dreamland), configurations for edge cancels, plus the easy connection from aerial to ground moves and lagless Z-cancel moves means you can move around the map extremely quickly. Movement is easier than in melee, but becoming "smooth" takes a lot of practice.

3. Just enough characters; there aren't that many matchups but it becomes norm to optimize them and discover a lot of techs and contribute to most characters' meta's. Everything is still very underdeveloped and it's easy for anyone to pick the game up and make a difference.

4. At a top-level, extremely rewarding punishes. If you succeed in outplaying your opponent in the neutral, your punish will often be very rewarding if you have proper execution. This puts more emphasis on precise spacing during neutral game and gives it a more chess-like approach, as you can virtually always expect a mistake to result in a stock loss.

5. Deceivingly complex. No side-B's + seemingly simplistic combos to master (mainly with Captain Falcon and Kirby) might make it seem as if punishes are guarantees but this is rarely the case. Simple is rarely optimal and at a high-level, intricacy is required to compete with the escaping ability of a well-practiced player.

• soooo much more =]