Star Citadel (2016)

A free web-based version of the 1980 Cinematronics arcade game, Star Castle. Offers a classic mode, designed to play as much like the original Star Castle as possible (i.e., it's really hard!), and a so-called "modern" mode, which is designed to appeal to players who perhaps didn't play the original: it starts off easier, and the difficulty increases in a more progressive fashion. The game supports all mainstream browsers, as well as running on iOS and Android devices.

Storyline

Trapped deep in outer space you must fight your way through the hostile defences of a vicious alien species to find your way home. Destroy the heavily fortified star castles before they destroy you!