save syncing for longer demos

spawnd demos are typically short-form experiences, but for longer or narrative-rich games, we recommend offering continuity between the demo and full game on Steam.

here are a few methods to consider:

1. local save (easier)

• generate a local save on the user's computer, which they can then import from the base game and restore their state.

2. generate transfer codes for Steam (more complex, not always applicable)

• allow players to export a unique code while playing the demo or at the end.

• this code encodes their save data (base64/JSON);

• the demo offers an UI to copy a "transfer code";

• this code can be "redeemed" in the full Steam game via a input UI, so it can decode and load this save state.

  references:

  • Reddit - WebGL savegame
  • YouTube - Unity How to save and load files using Json and Base64

note: spawnd currently does not yet provide a built-in save syncing API, so these are developer-implemented solutions.