This game is a good example of a lazy Atari ST port. Apart from not using the Amigas 32 color mode, the developers also didn't adjust the color palette to fit into the Amigas larger color space.
The Atari STs colors ranged from 0 (darkest) to 7 (brightest) for the red, green and blue channels.
The Amiga had a finer color resolution ranging from 0 (darkest) to 15 (brightest).
If you simply copied the same color values from Atari ST to the Amiga the colors on the Amiga only got from 0 (darkest) to 7 (brightest), which on the Amiga was only half of the possible brightness.
This resulted in a very dark game, as you can see in the variation image, where I kept the colors like they were in the game.