You can grab the update from Humble, or if you don't have the full version yet (?!) you can get it here.
Wow. So much. Where to start?
-There are image categories that you can load in the sim. There's the default, vanilla one, or there's others to try out, like a realistic set of images based on the planets in our solar system
-The planet images are completely mod-able. You'll find them in the data folder for the sim, and you can change / replace / add to them. Make your own categories, bring in your own images (maybe make a solar system with your face as the star?), whatever!
-There are more colors to choose from. Namely, all the colors. There's about 16 default colors, but you can change them or add to them at will with the new color picker.
-In addition to changing the color, you can change the image of an object
-You can increase the (visual) size of all the planets by a multiplier value if you'd like
-There's a mode where you can make the colors of the planets be based on their mass
-Finite trails are back
-You can turn trails on and off for individual objects
-You can change the color of trails independently from the color of the objects
-You can change the width of the trails
-You can change the color of the background / grid / UI / text.
-There's a new feature that writes out the world coordinates of your mouse for you
(Pictures / GIFs)
-There's a new menu that lets you take screenshots and GIFs of the simulator easily, and it's saved to your disk (in the data folder)
-Before, you always picked from Fixed Star, Star, Planet, Asteroid, and Dust. Well, now, the menu of objects you pick from to add is completely customizable. Add in more types, make an object type massless or massive, make it feel or ignore gravity, change its image, etc.
-You can even set an object in that menu to 'random' colors and just spam the world with confetti.
-The editor for changing an existing planet has many more features, too.
-You can now edit the position / velocity of an existing planet using your mouse.
-Massless objects now have a 'radius' value, which lets you define what size they should be.
-'Comment' system is now hacked in. Simply add in a planet with (a) a name, (b) m=0, so it doesn't affect anything, (c) make it ignore gravity if you don't want it to move, (d) you can even make it invisible, so you just see the text.
-If you select two objects, the menu will tell you their distance and force (this is a quick-and-easy way to have a 'ruler')
-You can save a history from t=0 (like before), or just save where everything is at a certain time.
-The code syntax has completely changed. My goal was to make it more readable and more powerful.
-Each line of the save-code now represents either (a) the general settings, (b) the properties of a *type* of planet, or (c) an object or group of objects you're adding
-You can not only add in single bodies... but now you can add lines, circles, and disks of planets in a single line! You want to add a circle of planets that is expanding outward and moving with vx=2? Do it! Want to make a disk with 5000 planets and see if your computer can handle it? Rad!
-Fixed the problem of merging planets. Now, even if planets have merged, the save codes will be accurate.
-The save files automatically copy into text files in the data folder of the simulator. You can copy paste from there, if you'd like. (Though note it only *imports* them when you start up the simulator... so beware of your changes getting overwritten while the simulator is running)
-You can 'quick save' a state with a new button I added, then 'quick load' it whenever you'd like. This would help if you wanted to quickly run an experiment several times.
-There's also a rewind button that moves the simulation back ~50 units of time. (Different from just setting the simulation to having negative time, since this is really replicating the old state... orbit lines included)
-You can also press control-z to undo your last change to the sim. (Undo an added planet, for instance)
(Nuts and Bolts)
-Various optimizations (planets are much more lightweight)
-Moar Zooming! You can now zoom in from x.01 to x100 (instead of just x.2 to x5)
-Collision animations are improved (a bit better looking, and also in the right place now)
-You can right-click on buttons
-Your settings are saved between sessions
-Menus now fade if you don't move your mouse
Okay, I think that about covers it. Suffice it to say, it's been a lot of changes. So give it a try, see if you can figure out all the new features, and, as always, feedback / comments / requests welcome!
-Update the web version to match
-More Science Equipment (protractor, etc)
(Sim Additions / Overlays)
-Polar Grid, Apsis view, eclipses (viewtopic.php?f=7&t=156&start=140#p2937)
-Inertial Mass != Gravitational Mass? (viewtopic.php?f=7&t=156&start=160#p3281)
-Changing Newton's Laws (viewtopic.php?f=7&t=156&start=160#p3281)
-Use dr/dt as a variable in force law (viewtopic.php?f=7&t=156&start=170#p3455)