When making this game, i tried to stick as closely as possible to the original graphics, and game-play. I decided against the idea of using 3D looking characters as i wanted to present the idea of having 2D characters in a 3D world.
Much like the original, this game has only one level which loops and adds on to your score. However, i am planning on making a sequel which will include additional levels with different enemy arrangements and items which can be picked up such as shields, new weapons and extra lives. I'm also toying with the idea of making it a sidescrolling platform game, although nothing has yet been decided.