Anyone else experience a serious lagging issue in-game? I've seen a few threads, but haven't found a solution yet. PCgamingwiki's page for The Nations is rather empty.

I can get past the intro, menu screen works fine. 'Might' have a bit of the flickering cursor thing going on.

I've messed around in the setRegTrouble tool, even set the Texture Limit to 100 (via 'Sicherste ( langsam )' settings).

Here are my specs:

Win7 x64
AMD 2.3 single-core
4gb DDR2 RAM
Nvidia Geforce 6150SE nForce 430 (128mb?) integrated GPU

The game is designed to run on Windows 95/98 I believe? Minimum specs are listed at 300mhz. I don't understand what the deal is here. I've had the game running somewhat smoothly on another machine, but it was a dual-core 2.1ghz with a slightly (very slightly) better graphics card. On that machine I did however have the menu glitch going on.

Any help would be appreciated. Anyone have any recommendations on Nvidia Control Panel settings??

Yes, go to bin folder and run tool.exe
Choose troubleshooting and then look attachement

Have you tried turning "Hardware-Scrolling" in the options-menu ingame off? That worked for me.
With that option activated, scrolling lagged horribly.