Ninja Gaiden Ragebound didn't seem to have any bugs or game breaking glitches. The game ran pretty smooth in both regular and hard playthroughs. I must be the only one who had zero issues with the game. That didn't stop DotEmu and Game Kitchen from sending over a D1 Update, which adds some features, improves some gameplay, and fixes a ton of bugs.
The coolest feature may be that when you go back into levels to find scarabs or dragon crystals, you can start from checkpoints. You can also re-try any section of the boss, as they are in phases. Hard mode can now be unlocked if you defeat Ryu Huyabusa in the first tutorial level.
They've added new dialogue to some of the cutscenes, and you can now disable hit stop and screen shake in the accessibility options. Hit Stop, is where the game slightly pauses upon hits for every strike. They use it for dramatic effect. The golden skins are also available immediately upon getting an S grade on all levels.
The bug fixes are massive, and you can check them all here. Don't worry console gamers. Your time is coming.