Since the last post, I’ve been working on what was probably the most challenging update so far, and version 0.4.0 is now out with the space section implemented!
This release completes the space portion of the game: you can now launch from the overworld, board and switch vessels at the space station, fight enemy crafts in first-person combat, hyperjump between sectors, become a Space Ace after destroying 20 enemy crafts, return to Earth, and rescue the princess to learn the location of the time machine.
You can download the game at the itch.io or the GitHub page.
itch:https://camilo-delcodigo.itch.io/open-sosaria
Github:https://github.com/delcodigo/open-sosaria
Space Section Feature Parity Achieved
The space section is now fully playable. Highlights include:
- Launching into space from the overworld
- Boarding and switching vessels at the space station
- First-person combat against enemy crafts
- Hyperjumping between sectors
- Progression toward Space Ace status
This was also one of the more interesting parts to implement because it required digging into Apple ][ Merlin Assembly. The original game mixes Applesoft BASIC and assembly, with BASIC making calls like CALL 29704, which then requires matching that address to the assembly code in the memory map.
There were also several cases where the behavior was not immediately obvious from the code itself. For example, enemy ships wrapping horizontally did not appear to have explicit wrapping logic at first. After looking at it more closely, it turned out to rely on a simple byte overflow and underflow technique.
Where Things Are Now
The important part continues to be how everything connects:
- The overworld map is playable, with rendering and player movement
- Towns have full feature parity, including working stores, the bard and wench, ponds, and pub hints
- Castles have full feature parity, including king quests, the jester key, ponds, and rescuing the princess
- Dungeons have full feature parity
- The space section is now implemented
- Saving and loading are working
- Random encounters are implemented
- The Ztats screen is available
- The ready/equip command is working
- Resurrection is implemented
- Weapons, armor, spells, and transport can be purchased
- The character generator is implemented
Next steps are:
- Making the time machine work
- Implementing the final fight against Mondain
- Adding sound
- Maybe adding some quality-of-life updates, although the main goal is still to keep the game faithful to the original
Thank you for following the development of this project. It’s getting closer and closer to a full playthrough!