How to ripping .pkn file about [Nexon Bubble Fighter]

[gameripper]

Thanks for letting me know! Couldn't you extract csv or dds files?
png files are possible, but others are not.

It is possible if you can figure out the key first. GAME RIPPER can only autodetect the encryption key if there's an uncompressed asset in a known format in the zip, but it can extract encrypted zip files with whatever files in it (so csv and dds too). If you have multiple zip files, and at least one can be used to autodetect the key, then you'll be able to extract the others as well (assuming all zip using the same key).

ps: PNGs are ideal for key autodetection, because they have a fixed 16 bytes long header and their data already zlib compressed, so it is likely that zip just stores them as-is without using further zlib compression. But it does not have to be a PNG, other types of files might work as well.

As for the rel_mission_bubble_rifle.zip,

Code:

**** GAME RIPPER ROM V1.6 ****
worker starting
worker synced
detect format 'rel_mission_bubble_rifle.zip' (time 844)
unknown engine format, fallback to brute force scanning
engine 'assetscan'
worker got command 1 (time 844)
worker load 'rel_mission_bubble_rifle.zip' isdir 0
getfile 'rel_mission_bubble_rifle.zip' 32280 bytes
  zip at 0, 87536 (compressed 32070) bytes, 'Dds/Maps/rel_mission_bubble_rifle/Plane01LightingMap.dds'
failed to retrieve encryption key, press F2 and specify manually
  zip failed to decrypt
worker game '?' loaded, RAM 0KiB allocated.
worker done (time 844, elapsed 0).
cleanup
worker got command -1 (time 21974)
worker done (time 21974, elapsed 0).
worker stopped
**** FINISHED ****

So it has a single file, which is compressed unfortunately, so GAME RIPPER can't reliably deduct the key; you'll have to specify it manually (by pressing F2 or by using the "-k" command line flag).

To autodetect the key on this zip in particular, try using bkcrack. That's a lot slower than GAME RIPPER, but you can specify the clear text (which is dds magic and maybe you can guess fourcc as well, the more bytes you specify the faster the crack will be) and it also tries some heuristics to make it work with compressed files. Otherwise it is using the same Biham and Kocher attack like GR.