The main change is that the forum is open again, and that you are once again able to submit fleets. Since 1.62 there are only a couple of very minor code changes (the dependency on SDL_gfx has been removed, and the game no longer draws a circle with a radius of 1 when displaying the range of a ship without a weapon).
A large amount of game rebalancing has been
carried out. It also runs quite a bit faster, and
there are numerous minor feature enhancements and
bugfixes.
Various gameplay changes were made. A much larger battle arena was implemented, ships now have momentum, capital ships can move, and it is harder for bombers to outrun fighters. A large number of improvements were made to aid tournaments. Various minor feature enhancements were made and a few minor problems and bugs were fixed. AI error messages are now dealt with more effectively.