It’s probably a recoilless rifle, doesn’t need to be anchored like a normal cannon.

I’ve played it two or three times, each time making it a bit farther. I think I made it about halfway at best.

Check out SpaceChem, matches most of your bullet points. It’s a level-based puzzle game like Opus Magnum though.

I have over 500 hours in Particle Fleet: Emergence. Very chill level-based game where you can slowly move forward and beat a map over an hour or so. All the Knuckle Cracker games have tons and tons of user content available so there’s no shortage of maps to play.