The game is a strange 2d arcade. It is not too playablile not 'cause all the levels are just test levels.
Before playing the game you have to create config file. Run the game at once and quickly quit (press ESC three times). It will create file game.cfg under Windows or ~/.hendehoh/config under Linux. Edit it and (optionally) add own music. If the game works badly, look at the hendehoh.log (or ~/.hendehoh/hendehoh.log). You can find something interesting there.
About the levels. In the first one you have to go down by the river, press the button there, get to the top, go right, get to the top by the ladder, go left, kill the ball, get the key, move right, fall, go left, open door and go into the exit. There is shorter way - you can use hole in the wall (find it using TAB).
In the second you have to use right bottom button to enable panel (p button). Then - kill droid (strange brown thing that goes using walls), get the key and go to the exit (use fourth button of the panel).

The third one is not too hard, too. jump into the river, press the button in the right, get the key and jump to the exit.
Fourth. Fly a few times to make flowers shoot all of their shells. Then kill them, get keys, open doors, go to the exit.
Fifth. Hanoy towers. Move all the blocks from the first place to second or third.
Sixth. Test level.
You can report bugs, write messages, etc. at the page http://www.sourceforge.net/projects/crazy