Can they all be solved?
The first release of Cogismo Logic Puzzles shipped with 229 level 1 to 4 puzzles. All of these can be solved. I know because I’ve solved all of them. The first release of Cogismo shipped with 43 level 5 puzzles. I have solved about one quarter of them. As for the other three quarters, there is scope for you to be the first in the world to solve these 😉