Crypt of the NecroDancer: Amplified is a DLC prequel for the rhythm-based roguelike that brings with it a brand new zone full of dangerous enemies, pet-like familiars that fight by your side, as well as a whole bunch of new weapons, armor, and bosses to toy around with. The expansion also launched with a brand new character named Nocturna, and the promise that more characters are coming in the future.
As you can probably guess from the title, the first of these new characters called "Diamond" has now been added to Crypt of the NecroDancer: Amplified along with a modabble hard mode. If you're interested in all of the patch notes you can find what you seek on Steam, but if you're just interested in the short version here's everything concerning the new character and hard mode:
New character: Diamond
• Complete zone 5 to unlock
• Use key combos to move diagonally
• Up+down uses bomb
• Left+right uses item
New mode: hard mode
• More enemies in each room
• Most rooms have a sarcophagus that spawns enemies and is immune to weapon damage
• Exit rooms have two minibosses instead of one
• Boss floors have minibosses added
• No trap doors
• Moddable via necrodancer.xml
If you don't know much about Crypt of the NecroDancer or its expansion, but you feel like the concept has some potential, I would recommend heading over to either Steam or the official website to learn more. If its just gameplay that you seek, however, here's the latest trailer for the Amplified expansion. Enjoy!