Zanac [NES] and Tyrian [PC] were the two biggest shmups in my childhood, and Tyrian owed a very large debt to Zanac that they acknowledged a few different ways. One of the biggest influences, though, is that Zanac's maps are huge
, and apparently Tyrian's developers were shown Zanac by the publisher partway through development and told not to bother coming back until they could beat the standard it set.
For awhile now, I've been working on reverse-engineering how Zanac fits its data and behavior into as small a space as it does. Now that I've actually reached a point where I have at least one complete result, it's worth making the project "real" and giving it a thread here.
At the time of initial post, I've managed to reverse engineer its tile and map graphics formats enough that I can extract level maps as (50-70,000 pixel tall) PNGs. (Above: the first three or four screens of level 1)
The immediately pending tasks are to turn my little experimental scripts into releasable map- and graphics-ripping tools, and to refine the notes that didn't make it into my graphics-hacking documents into Data Crystal tables.
Longer term, the map information also clearly influences gameplay in various ways and those caverns are still unexplored. Once that gets sorted out, map-editing tools become a real possibility.