Ah. It was an Apple II game, not an arcade game.
Armor Alley is a similar (if not identical) game which I would also be interested in an emulator for.
There’s actually a great true story about the connection between Battlezone and the original Star Wars vector game. Read about it here (search on the page for “Star Wars”).
In any case, a classic old game which has a lot of replayability is Elevator Action. Very simple conceipt, but a surprising depth of gameplay, and lots of rules about how the world works. For instance, the fact that you can rid on the top of an elevator, but can’t control it… the fact that you can crush bad guys under elevators, can kill them by shooting lamps which fall on their heads, etc.
Agreed, that was my favorite game from back in the day.
My vote is Defender. Appears to be a simple ‘don’t die’ shooter, but there were many ways to milk scores while delaying the level end, redistribute your captured survivors to make them easier to defend, kit enemies to cluster them and kill easier, delay the dreaded ‘all angry aliens’ level, etc.