Here are two Robotron remakes from Mersey Remakes called R-Tronic and R-Tronic 2: Armageddon. The first R-Tronic game is around 7 MB and you have to shoot at all the invading robots. In R-Tronic 2: Armageddon, you shoot at robots while trying to rescue humans. R-Tronic 2 is about 10 MB. Both games are a lot of fun and are really well done. You can check out screenshots on the author’s web site: http://rtronic.merseyremakes.co.uk/.