Thanks for taking the time to play Eclipse War! I appreciate the feedback.
Retaliation rules are based on the range of a unit's equipped weapon, so a 2 range weapon like a bow can't counterattack a 1 range weapon like a sword and vice versa, while some weapons have multiple ranges they work from like the fire tome which can attack at one or two range.
Stats & Inventory can be checked with middle mouse click which is a little intuitive, but I'm surprised people are getting most of the way through without knowing that. I hotpatched that into the tutorial last night but if you downloaded before then you would've missed it.
When you say the river was pathable do you mean you could completely walk right through it or were just a couple of tiles pathable? There are a few tiles that look like they probably shoud've been water tiles but are actually normal tiles, but you shouldn't be able to walk straight across the river.