Some games are distributed in .zip packages. Lots of these have file names with non-ASCII encoding characters.
Most zip files are not using Unicode, so they need a special procedure to be unpacked properly.
unar (from The Unarchiver) automatically detects zip encoding and it's available on most distributions. It also supports rar files.
Commands for specific encodings:
LANG=ja_JP 7za x filename.zip cd gamefolder convmv --notest -f shiftjis -t utf8 -r *
LANG=zh_HK 7za x filename.zip cd gamefolder convmv --notest -f cp950 -t utf8 -r *
zh_TW and other should work fine too.