Shadow Knights is an early ID Software game made using the Dangerous Dave 2 engine, itself modified from the Commander Keen 1-3 engine. Due to having to be cut down to fit on a floppy disk and to meet its release date, it lacks a number of features, such as appreciable story elements and animating tiles, much like Dave 2.
This section lists the major file formats used in the game.
- B800 Text - 4000-byte internal files are text screens shown at exit.
- Commander Keen 1-3 Level format - LEVELxx.NIN are game levels.
- Commander Keen EGA Header EGAHEAD.NIN is used to read graphics files.
- Dave 2 Tileinfo format - information about the properties of tiles are stored internally in the executable
- Dave 2 Tileset format - EGATILES.NIN contains the game tiles.
- EGA Font format monochrome font used in the game is stored in the executable.
- Inverse Frequency Sound format - the sound file is stored internally and uses Apogees 'inverse frequency' sound format.
- PIC format version 1 - the 640x200 end screen graphic is in this format, compressed with RLEB compression.
- Full-screen planar EGA Most graphics are in this format, compressed or rearranged in various ways. For example, the sprites and the font file are this compressed with ?RLEW compression?.
- ?RLEW compression? This is used to compress most graphics.
- Text is contained in the executable, the executable is compressed with LZ compression, and can be uncompressed with UNLZEXE.
Shadow Knights is intermediate in development between Commander Keen 1-3 and Commander Keen Dreams which followed it. Though basic, it makes use of several changes in format that are used in later Keen games.