Level 12 called Temple of das Lichtgods has two very difficult stages. That's because stages no. 4 and no. 5 are upside down! The real problem is that you aim normally, so after a few hours of playing you need to aim in totally diffrent way. But here comes the solution:

This exploit is based on how Windows works, so I don't know if it works on MacOS.

Just press Ctrl+Alt+DownArrow
That's it. Now your screen is upside down, so you can aim like in the rest of the game.
If you passed this part - don't pannic. To make you screen normal just press Ctrl+Alt+UpArrow.

I hope I could help. Leave Like and add this guide to favourites, if you enjoyed it.

Thanks.