* spoiler alert *
There are layers of mystery in this game that have survived so long because of how challenging it is and how few people beat it, so while I won't disclose everything I could, the answer to this question will still spoil mysteries for players that have not progressed very far in the game.
The final stat you haven't discovered yet is...
Consecutive air parries
You can perform a parry by hitting the arrow key facing an enemy or enemy projectile that is about to hit you. So if you are about to touch an enemy from the right side, you have to hit the left arrow key right before he would otherwise kill you. (Only Left/Right matters, not Top/Bottom. Try visually dividing the enemy in half vertically.) If you are successful, the enemy will freeze in place for a few seconds and will not harm you.
This precision of this move is quite challenging, so it's no surprise if haven't encountered it yet. If you have, getting two in a row without touching the ground is even more difficult.
A white Later, when you are close to beating the game, you will uncover a new secret that lets you do an even more advanced move following a parry, making it easier to achieve consecutive air parries. This advanced tactic is required to beat many of the challenge levels (111-120), which are only unlocked after beating every other level with rainbow flower times.
As I'm sure you've discovered, when you are close enough to the rainbow time (often within a 3 or so seconds) you will see the ghost of a ninja beating you to the finish line. This is the replay of the Dev time that you must beat, and watching it will often reveal new tricks and strategies required to approach dev times on other levels.