Orange, from Ceramic Shooter: Electronic Poem and Composition Piece developer Theta Games, is kind of like Ed Logg’s Asteroids, if instead of clearing away hunks of space rock you were being set upon by the Blob. That said, it controls more like Robotron — or indeed Echoes. The game also supports mouse aiming, which is probably the way to go.
The storyline sets you, essentially, in the Vietnam War. The amorphous mass that threatens to smother the player’s ship is supposed to be analogous to the jungle, and the player’s shots analogous to agent orange. The game is set to a tranquil soundtrack, though at times becomes tense as the screen chokes up with obstacles.