There's absolutely nothing wrong with that version of TANX. I and several others have used the download from that website for over a decade. That version was better than the browser as it had full screen options, no advertisements and some other nifty features such as matching your native resolution which ultimately made the game feel smoother and less sluggish. It was specifically for Subscribers only, meaning you couldn't connect to play without a FOD membership, you could only login and spectate ect. 

I used that version since 2008. FOD for some reason removed it a long time ago from the old Flyordie.com/tanx page without any explanation. The MODS were well aware of many of us still using it and never moaned so my guess is that it was removed because they had intended on converting TANX to HTML5 instead of the JAVA it used all the time.

Either way, that download is safe. I've always kept it because even though tanx is indeed gone now ..you can still play against the BOTS in practice mode. Just brings back memories.

Funny thing is.. in 2008 I had no internet for 3-4 months, but I had that on my PC. Before my internet went off I was a total beginner in TANX, had barely played it for a couple of months. I played that offline practice mode for a lot of hours when I was offline and when I went back with internet in 2009 i was drastically better, faster and I flew up the ratings far quicker than I did before. A lot of people didn't believe I was the same player because I was so much better after a few months of inactivity lol. Even tho the game is gone you can still have some fun on that little practice mode until it comes back.

And it will be back. even if I have to pay a Developer myself to bring it back elsewhere.