- Sunburst Contamination (with Fredrik Ramsberg, together as "Att Scoddams"; 1988 (stated as 1982 in the game); Commodore 64).
- Z-code port: (porter: Johan Berntsson; 09-Mar-2007; Z-code 6).
- The Dragon and the Troll (1987; Commodore 64).
- Z-code port: (porter: Fredrik Ramsberg; Z-code).
- Vacation Gone Awry (Johan Berntsson, Staffan Friberg, Fredrik Ramsberg; 1988; Z-code).
- The Hobbit: The True Story (with Fredrik Ramsberg; 1993; MS-DOS).
- The Temple (2002; Z-code). IF Comp 2002: 9th place. XYZZY Awards 2002: finalist for Best Individual NPC.
- Drakmagi (2003; Z-code, Glulx, MS-Windows). Swedish.
- Vanyar (2003; Z-code, Glulx, MS-Windows). Swedish.
- The Big Scoop (2004; Z-code). IF Comp 2004: 13th place.
- Swedish translation: Pangnyheten (2004; Z-code). Was developed concurrently with the English version.
Johan ported these games to Z-code:
- Stuga (with Fredrik Ramsberg) (Viggo Eriksson, Kimmo Eriksson and Olle E Johansson; 1978; DEC Basic).
- Sunburst Contamination See Author Credits above.
- Co-wrote the Ozmoo interpreter.
- Co-wrote the PunyInform library.
- bas2inf is a utility that converts BASIC source code into Inform 6 source code. It was written in Ruby by Johan Berntsson and tested with the Sunburst Contamination game. Download bas2inf.zip.
- The Isle of the Cult (Rune Berg; 23-Dec-2004; TADS 2).
- Swineback Ridge (Eric Eve; 22-Apr-2006; Z-code).