My opinion as newbie/casual player. I was playing OG last 2 days.
It is fantastic ; units, maps, options. Scenario in exotic places, and conflict I haven't hear about (dont worry im aware some are fiction:) ). Didactic value is great, esp. for someone like me, who have aversion to second world war.
I adore the 2d graphics.
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I printed this manual:
http://www.open-general.com/doc-manual.php
I was confused about how exactly work Close Defense and Range Defense. And I check some PG2 forum for some explanation.
I suggest to update Manual at least with this two information (Close Defense all cases of use - maybe in some table format? Mention that Range defense is add to ground defense if attack is further away than from abut hex). Otherwise you left player wondering what exactly the two main stats do in game.
How initiative works? its who shoot first? or who win Initiative battle, grant some Attack and Defense bonus, then combat is solved simultaneously (you could just receive bonus or not)
I still don't have a grasp how the Attack vs Defense is affecting the battle outcome. I think there should be some guideline as well, .f.ex. if you have 2 attack more than enemy defense then you have roughly X% for kill and Y% suppress.
This amendments to manual would help a lot new players like me.
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Unfortunately playing OG is wearisome, because of only one thing. After each of my turn I am waiting quite long time for AI movement to end. Even if AI doesn't seem to make any brilliant decision, it just move units forward.
Part of the burden is lack of any AI progress bar or indicator, I just see "AI scan" at the bottom.
Waiting for AI, wouldn't be so bad. If I could in this time, f.ex check the units stats. I refrain from trying to do it, because I have CrashToDesktop twice (last time just minutes ago).
AI is quite competitive (compare to other games), he just think too long. Its single player game.
Not sure if that make sens, but maybe could you add options for "Fast, but stupid AI" ? where AI dont do any of this scans just move units forward and attack nearest target? This would be good for new players, that just want to have fun, and make lots of mistakes anyway. [ I lost final battle in tutorial campaign

As for now I contemplate my life choices quite too often, waiting for my turn, to continue playing OG.