Been playing the new version a bit, and found some issues:
The 4 AM mix begins at world 2, and you start out fully loaded with weapons. You can also just jump down the ladder and approach the door to get the "World 1 completed" message.
That repeating whistling sound I've mentioned a hundred times, it's still there
I downloaded and added the full music pack, and I get music at the title screen and when I see the shop-keeper, but the intro is still silent.