Planet Enforcer - Android-Apple-Windows Phone
Though part of the kick of the original Defender and Stargate were the complicated controls, just would not be feasible on a cell phone for portable play. This game for touch screen pretty decent. Buttons include Fire, Smart Bomb and the outstanding Reverse Direction button. The virtual stick for up and down also handles thrust. No Hyperspace, you have to stay and fight the onslaught, but there are Novice and Practice modes.
Note that the Williams explosions and radar scanner retained.