Very good DLC. It comes with an additional area (which is mostly there for grinding and Ascended gear tbh), a new dungeon filled with what makes CrossCode itself (which is both a good and a bad thing because that ALSO means the puzzles are back). The dungeon's bosses are also very fun to fight, specifically the final one which is very cool

The added story content is very nice too! However most of it is spoilers territory for the base game, so I won't say anything in case someone clicks here without having finished the game.

TL;DR: it's worth it! Just make sure you get the good ending in the base game