Lost Numbers actually had the most fun level designs of the game for me. That combined with the new presentation and music made me really excited going through it - it felt like a huge change of pace that the game needed. This sort of grinder to a halt with the final boss, though. It’s genuinely unplayable, which really sucks and soured the entire experience. The ending to the story is also…not good, but the story already was a sort of loose way to tie it together? So should I really be complaining about it? Either way, it felt really underwhelming after beating the final boss - and yes, the actual “ending” to the game is locked behind this DLC, there is not even a credits roll in the base game.

The bundle of the DLC with the base game on Steam cost less than the base game by itself for me, so I only recommend playing the DLC that way. You have no reason not to in that case.