well people, now my opinion.
Commandos BEL was helluva hard. I loved it tho, and still do. as a matter of fact, I'm trying to convince a few schoolm8s to play on a lan with me. I never managed to finish it tho.
Commandos BTCOD was even harder. But I loved it even more. I got to the before-last mission, then gave up.
Commandos 2 was waaaaay to easy. I finished it in about