Now you can do targeting and race mssions on Venus and Mercury (a total of 4 new missions)! I have also fixed some bugs and improved the look of Mercury and Venus.
I hope you're not afraid of heights! Fly up to the top of the Mercury tower, where you will find the blue question mark that will trigger the Tower Target Drop, where you walk out onto targets, hit them, and fall down to the next one! Note that you will fall more slowly than normal because the gravity of Mercury is pretty low (only 0.38 G or 38% of that of Earth). If heights aren't your thing, you have many other missions to choose from!