When you degenerate a Digimon, Aptitude is added to it. This raises the level limit of the given Digimon that was degenerated, although the level limit raising fluctuates based on the Digimon type. This will allow you to level-up your Digimon to higher levels, thus making them much more powerful.
Secret passwords
Give the password to Valkyriemon inside the DigiColiseum.
20060402
Obtain 100% Scan Data for DotFalcomon.
70307991
Obtain 100% Scan Data for DotMirageGaomon.
20406002
Obtain 100% Scan Data for Sukamon.
02619020
Obtain Legend Sword, Legend Robe, and Legend Ring.
Silent Digimon
From time to time, on the top screen of your DS, a Digimon will talk about any given item in your farm. However, sometimes they appear on-screen to say something, but end up saying nothing at all. A glitch, perhaps?