Vulgus is an interesting vertically scrolling shooter developed and published by Capcom in Japan in 1984, and was later released in North America by SNK the same year. The game has the distinction of being Capcom's debut video or arcade game.
The player controls a spaceship with a single objective: destroy incoming enemies. The vessel has two different weapons: a primary weapon with infinite ammo and a limited supply of bombs. By picking up the "Pow" icons, which sporadically appear throughout the levels, the player can replenish supplies. In contrast to most other titles of this genre, the game does not have distinctive levels. Instead, the background alternates between the surface of a planet and a space field. The game repeats with increased difficulty until the player has lost three lives. Thus the game can be considered, in terms of gameplay, somewhere between a fixed shooter and a scrolling shooter. Because the player's ship is destroyed if hit only once and there are no continues available, it is generally a better strategy to avoid enemies than to try destroying them.
The Pow icon is re-used in many other Capcom games, like 1941: Counter Attack, Bionic Commando, and Exed Exes. Likewise, the Yashichi enemy has made later appearances in many Capcom games, usually in a more benign role as a power-up. (Wikipedia)
Vulgus is pretty simple. You just pilot a spaceship and blast countless enemies. That is what is fun about this game. There is nothing complicated, just pure blasting. You only have two weapons, your blaster, and a limited supply of bombs. This title uses the time honored top-down vertically scrolling format. The background moves eternally forward, but you can move all around the screen, and can make the screen scroll both left and right. Your enemies consist of an assortment of fairly realistic looking spacecraft, some of which have a distinctive 'insectoid' look to them. This game is endless and it doesn't seem to have a level format. You just move forward and shoot. The backgrounds will change from time to time from planetary surfaces to space scenes and eventually they will start repeating once you blast this particularly large alien formation. (arcade-history)