Atari 2600 - Empire Strikes Back remake

While struggling to master the 2600, i figured i'll try to do a remake/update of a known 2600 game. One of the games i enjoyed playing on the 2600 was the 'empire strikes back' game by Parker Bros, but i was always annoyed by the very blocky walkers. So i did a little test on my version of the game. Its far from finished, and so far it only features a ship you can control and a scrolling background. I hope i can add some smoothly animated walkers in the future, but first i have to find out how to clip them properly on the edges. Anyway, here's a screen.