Pro Unique gameplay
Crypt of the NecroDancer is a dungeon crawler that is also a rhythm game. Your character can move, attack, and use special abilities only to the beat of a level's music. This means you have to split your attention between listening to the music and watching enemy movements. If you miss a beat your character won't do anything, but your enemies still get to move and attack. While the enemies are bound by the same rules as you, they won't ever miss the beat. Fortunately enough, they're always bound to a rhythm, so learning an enemy's rhythm is the key to defeating them. As a result, the gameplay stands out in both the roguelike and rhythm game genre.
Pro Lots of options for different skill levels and play styles
Characters such as "Bard" provide an easy mode without making the game feel plain. Other characters provide an extreme challenge for more advanced players. Lots of different weapon and armor combinations keep the game feeling fresh and support different play styles. Players also re spawn after each level, meaning a less skilled player is rarely out of the action for too long.
The game also has great tutorials for both basic and advanced strategies and a good difficulty curve.
Pro Combines rhythm-based gameplay with dungeoncrawling
Crypt of the NecroDancer is a rhythm rogue-like dungeon crawler. All actions can only performed on the beat. Adding rhythm as an element to a dungeon crawler allows having each enemy move in a different patter related to the beat and interesting powerups such as tempo increases.
Con Co-op can be unncessarily difficult
Coop requires players to share money and items, which can leave two under-equiped characters instead of one well equipped character. Players also share one screen, meaning they need to agree on which general direction to proceed in. Going in different directions can cause players to get stuck or attract multiple groups of enemies. Players also share one beat counter, making combos harder to achieve.