One thing that came up when I played it was the controls actually: in the actual PC game you would select and execute command with the left mouse button.
You chose to do it like starcraft with right mouse button. That alone would be ok but using the menu designed for PSX was kinda confusing: left mouse this, right mouse button that, how do I get out and in ?
There should be a back arrow and stuff… in short it wasnt that easy to use
Ah nicely done. 
I want to help as I think it’s a big project to get done and polished by yourself and I want to play it but I’m quite limited with what I can do at the moment. If you raise issues I think I can help with I’ll have a go but I think your other ones are beyond me at the moment, It took a fair while to find out where bit and pieces were.
Out of interest what’s the issue with Slick2D’s A*, it seems to work fairly well?
I kind of agree with Cero about the buttons to use on the sidebar. I quite often click the wrong ones. I find the left click to open a page and select an item fine, and then the right click to close a page but then when you have a building selected it right click to open a page. I can’t really think of a better way to do it though.
It works too well for me. ;D
A* is being slow for big number of units and frequent path searching. Also it causes freezes when trying to find path into blocked area. I think we need another pathfinding algorithm which may be less precise but fast. And also I think it could be bi-directional to be able to determine freezing situation described above.
Bump!
If you’re still on the case of path finding, might take a look at jump point search. If you have an 8-way unweighted grid (looks like it), it’s often cited as an order of magnitude faster than A*.