Almost all current engines are similar and built for the same tasks (stockfish, lc0, slowchess, comodo...). And I only heard about a few unusual engines
Crystal: based on Stockfish but used for problem solving
SimpleEval: as I know also built on Stockfish, uses only material counting (1, 3, 3, 5, 9) as evaluation
Boris-Trapsky: plays not the strongest position, but position in which a person is likely to make a mistake
Maia: try to play like human
There are also different game modes in Komodo, but they are not free.
From serious and large projects, I heard only about this. I would like to know if there are similar engines, it is not necessary that the engine plays very well or was created by a large company, the main thing is that it is not ordinary.