Vimana is a space shoot'em-up with a few twists to the original concept. The actual game itself isn't one of the best, most of the art reminds me of various kitchen utensils aimlessly drifting in space.
The major differance is in the way you use the weapons, they are "charge" weapons which means that if you hold the shoot button for a while you increase the spread of your bullets. You have this one weapon throughout the entire game but you can upgrade it with pickups to make the bullets more powerful.
Another differance is the smartbombs. When used, a ring of balls appear around your spaceship and when enemies enter the screen the smartbombs automatically aims to the enemy and take it out. Your ring of smartbombs usually last for 10 seconds.
The bosses in this game are quite original too. If you think all shoot'em-ups are the same you should give this one a try. There are no known conversions of this game to my knowledge, and unfortunately the sound code is on a protected MCU so emulation has yet to get any sound out of this game.
Music composed by Toshiaki Tomizawa
Click here to read the background of the name Vimana. (From EmuXPress)