Not bad once you know how to play it, efficient pleasure considering the lenghth of the game

I don't find it good...

While i agree with others that sound and music is missing, which is an important part of a game, for me the biggest problem were
1. the graphics, they looked way too simple
2. the gameplay, like the reset thing. The moon resets automatically once it hits another planet, but it doesn't if it flies in outer space, which was really annoying. Also some kind of tutorial levels that ease you in would be nice.
3. Some kind of menu

nice concept lack of sound and music too less levels need better resst button that you can press r to resst 3 stars

As it is, it is a good concept for a game, but not a good game in and of itself.
Currently, it needs 2 things to be a decent short game: MUSIC, and SOUND. The game is just too quiet. sound and music set tones, moods, tempos, things that help the gamer get into the game they are playing and hold their interest.

More levels, a timer instead of a reset button for off-screen launches, and a difficulty setting would be a plus, but aren't needed.

A story would be great, (I'd like to know why I'm launching the moon at the sun or planet), but isn't needed.

Lastly, and this is only a personal opinion (and in no way reflects my score), I'd change the small moon we're launching for perhaps an artificial satellite or exploratory probe of some sort