The game should automatically save its progress. The latest version, v1.0.13, should warn you if it's having trouble saving your progress for some reason. (Previously it didn't say anything.)
Annoyingly buggy. The guy at the pub steals all your boots, regardless of how many he says things cost. I have a zero score despite being halfway through the moon. Diggers won't pick up items that I uncover. On lower levels the grid squares become so small that the clickable area sometimes can't be found, so I have to abandon it and go back to town.
Buggy as hell, menu items don't even fit on the screen. No instructions on how to play (took about 15 goes before finding out that the mouse button is 'fire'). After the first few ships, all collision detection goes out the window and you can fly through ships and the earth. Awful.
The battle for the last planet in the first system is buggy for me. The 4 enemies' health stats are NaN, Nan, -0.92 and -0.43. When I battle for the planet, the battle can take 30 mins to defeat my ships, and the two remaining enemies just sit there with empty health bars.
Well that´s for sure. Did not even check it yet to be honest.