I'm new to the game but I've found the "First Casemates: CSS Virginia" to be inordinately difficult for its position in the list. It feels like the first missions are supposed to be tutorials of sorts, explaining certain concepts and then there's the two ironclad missions. I was able to make a turreted ironclad that eventually beat its opponent into submission but the other direction escapes my grasp and in any case it's just tedious attrition. They're cool and I appreciate the effort that went into making them but they're more of a challenge mode that makes sense later in the progression than an early mission. Otherwise to make it more fun, I'd look at how to keep it from dragging on forever. Like don't even allow bulkheads beyond minimum and make damage control particularly bad considering the era. Especially for a ship with a foot or two of freeboard, flooding should just end them. Allowing full-size secondaries on casemate ironclads gives them more firepower or in a more historically speculative direction, sticking a spar torpedo on front or a plain old ram.