This is the worst custom map I've played. The detail is completely lacking, there is no skybox (just a ceiling with a moon on it), it's mostly omnidirectional (you can only go up, then back down, repeat), the textures aren't right, the lighting is off...I could go on and on. Normally I would explain how to fix all these but judging by the fact the designer said he spent an "extra 12 hours making it better" I don't believe it would help much.
original was better.
To map author: use light sources, make the map as it was in mod.