Unfortunately, debugging Izuna 2 was not as easy. Atlus explains that there are "moments where we catch ourselves staring at the screen, mouth slightly agape, eyes unblinking, with a few choice words running through our heads."
Finding and fixing bugs is always an arduous task, and Atlus already had to identify and fix bugs that had managed to make it into the Japanese retail copy of the game. Given the fact that Izuna 2 is a game with random dungeons and enemies, this task becomes more challenging because specific bugs only occur under very specific conditions
To make things worse, due to its coding Atlus wasn't able to use a debug cheat menu for Izuna 2 to instantly power-up. Instead, debuggers had just a one-hit kill option (that didn't work on bosses) and a floor skip to work with. When they died or the game crashed, they lost all their items and money just like real players would.
Thankfully, all this work means that American gamers will be getting less bugs and a game that's even slightly improved over the Japanese release. For more details, like how many times Atlus told testers "That's not a bug, that's the way this game works," (seventeen) don't forget to follow the link at the top of the page!