Space Bugger?
Warp & Warp?

Thanks ! Its neither of these games. The game I mean has better graphics than the two games you mentioned. Its aliens are made up out of a couple colours. More like the aliens in Galaga/Galaxians. Also the game I mean is a Table Model with glass surface with on opposing ends the controls for the players and on these same sides their spaceships moving left/right (and possibly up and down) shooting bombs into the middle field of circling aliens. I took a screenshot of Galaga and edited it so it looks like the game I am looking for :

when I was ~11 years old (around 1979/1980) me and my family went on holiday to England and in an amusement center I played with a game whose name I'm trying to find now.

Description: it was a table model game (quite low) with glass surface and the game was projected through the glass surface. It was a space shooting game with circling 'aliens' and both opposing sides of the table had controls and both players could shoot at the 'cloud' of aliens at the same time. So NOT like the normal Galaxy/Galaxian setup where there is a ground and a sky and only one player (at one time) shoots from the ground into the sky.

Anyone know which game it could have been ?