Having only 10 weeks to create a game and considering the fact that every person in the team was a full time student, every choice had to be thought out to have the greatest impact. Almost every mechanic has at least two uses in the game.
One of the prime examples of this is the ultimate attack. In the original design, the creation mechanic was always meant to have more of a defensive style, but it also had a way to deal damage to the boss. By creating a diamond shape, the player could spawn a bomb to attack the boss, in the event the player did not feel the need to use the drawing defensively. This, however, felt very cheap and players would not know how to make the bomb unless explicitly told.
After some early playtests, we found that players wished to have a way to clear the created objects from the stage. So what if, instead of having two different mechanics, we combine them? Thus came to life the ultimate attack, where the player can choose to throw all of the crates on the stage towards the boss, dealing damage based off the size and quantity of items thrown. And what better way to combine this again with other mechanics, by having the resource to use that ultimate be linked to the gravity and bullet hell mechanics?
This created an entire system, where every mechanic is interlinked, and no mechanic was simply there to fill the criteria with no actual purpose.