Gee, I missed this the first time around. I heard the game was supposed to be vaguely like Super Metroid.
Vaguely, yes. It's structured into levels rather than being a single large world, so perhaps closer to Castlevania. The gameplay gets rather repetitive for my taste at times, but I'm sure some people will like it.
It makes me wonder why no one has apparently released a patch before now.
Dunno. I figure part of it is the game was forgotten once the Lupin craze ended. Overall, the game hasn't proven overly difficult to hack for an experienced hacker like me. I'm only taking my sweet time because WLA is broken and I'm too stubborn to use xkas...
Was the game text compressed at all?
No, but the text was tricky to find because the charset is 16-bit (little-endian) and non-contiguous, like this:
Notice how it skips over 1000-1F00. That's because trying to print them will print gibberish characters (the lower halves of the characters in the first row combined with the top halves of the characters in the second). I didn't find the text until I reverse-engineered the code enough to find where it was pulling the text data from. Once I found a block of text in the ROM, though, it was just a matter of changing bytes and seeing what they printed.
The font, on the other hand, was
compressed. But instead of bothering with decoding the compression, I took a suggestion from Lakmir (a.k.a. Gideon Zhi) and simply stored an uncompressed font in one of the game's many blocks of free space and just had the game load that at the appropriate time.