英语渣表示作者好像说，每层的BGM会变，比如这个视频前半段是普通听到的，后面是在一些特殊情况下听到的。

贴上原文，希望大家能帮忙翻译下，真的好难翻译啊。
Taste the Sodden Hollow!
So ive mentioned in the past how music in rebirth would have more depth than the previous soundtrack, i wanted it to complement the living environments and also adapt to what was happening in game.. well the latter is something we are currently playing around with, i call adaptive layering.
here’s a good example of it using the 1st spoiled track “Diptera Sonata”, the 1st 50 seconds shows the track as youd normally hear it, the 2nd half shows an adaptive layer that comes in when there are lots of enemies on screen with you, usually in larger or extra large rooms.
the layering aspects havent been mastered yet so excuse any odd volume issues with them.
ive avoided posting the new caves track because i wanted the game to be in a near final state visually so you can all fully appreciate how well the track complements the visuals of the game. i told matthias i wanted the track to bleed with damp echoey haunted goodness… and this is what he made.
I give you “Sodden Hollow”
its probably best to listen to that while looking at a gif of the caves in almost all its dark damp glory… (technically there is a curse of darkness in effect, so the caves wont be that dark, but it looked so good…)
its still missing puddles, mushrooms, rocks and other debris.. but you get the idea. the caves will also feature a more bluish tint and feature a few non enemy critters (tiny ones) scurrying around.
THIS is the game i wanted to make 3 years ago :) … but sadly didnt think enough people would care to make it worth anyones time… so much more to come.
im also loving the lighting…. oh so much.
what do you want to see / hear next week hmmmm?

放两张截图，应该是黑暗情况下的房间展示
动图建议看原网址
http://bindingofisaac.com/

话说地图精简了好多。

前排围观

简单说几个可能没用的：
前50秒的音乐是普通版，后面的是在面对特别多怪或者特殊房间时播放的
图片中的洞窟层原本不是这样的，变黑是因为新一代"黑暗诅咒"的效果
这种特效作者三年前就想做出来了。。
学生党词汇量有限，只能等等大神全文翻了= =

这种黑房效果更有洞穴感

音乐风格更像一般的主流游戏了？

围观支持

卧草，这种房间遇上一堆蜘蛛什么的怎么打啊。。。

感受一下这腐烂之空洞吧！
我之前已经提到过，重生的音乐会比以前的音乐听起来更加深邃，我希望它可以对环境的渲染有所辅助，并且能适合游戏中所发生的情景。那么最近的就是我们现在正在鼓捣的东西，我在寻求能适应游戏环境的分层←渣翻凑合看吧
这是个很好的例子，它应用了第一个破坏性音乐(?)“Diptera Sonata”，音乐的前50秒就是你（在游戏中）正常听到的那样，接下来的一段展示的是一个适应环境的分层，它会在你面对很多敌人的时候播放。这段音乐通常会出现在加大房间中。
在音乐分层方面，我们还没有完全掌握，所以请忍耐一下一切奇怪的音效的问题。我已经避免了制作新的洞穴音乐，因为我想让这个游戏的视觉效果接近一个最终的状态，这样你可以完全喜欢上音效对视觉效果上的加成。我已经告诉matthias我想让音乐听起来有流血的感觉，潮湿的回音扰动着你的善良内心（←我已经不知道怎么翻译了- -）...这也正是他所做的。
我给你的“腐烂之空洞”
在看洞穴的gif图片时听这些音乐可能最好，后面开始各种中二了我不翻了(╯｀□′)╯（┻━┻