RetroAchievements Multi-Set Support

NOTE: This is likely blocked by the implementation of:
Add RetroAchievements Game Page ID to LaunchBox Games Database

📋 Summary

Add support in LaunchBox for RetroAchievements multi-sets, allowing a single ROM to display and track the base achievement set and any available subsets without requiring separate game entries.

❗ Problem

RetroAchievements recently introduced multi-set support, which allows players to earn subset achievements without patched ROMs.

🔗 https://retroachievements.org/forums/topic/34021

Currently in LaunchBox:

• Only the achievement set tied to the ROM hash (base set) is shown

• Subsets must be tracked as separate game entries to get their own achievement badge

• This leads to duplicate games and fragmented achievement tracking

• Subsets are not visible in key areas such as the game details pane or pause menus

This workflow no longer aligns with how RetroAchievements now functions.

💡 Proposal

Enhance RetroAchievements integration to support multi-sets:

• Detect all available achievement sets (base and subsets) for a single ROM

• Display all sets within the Game Details view

• Allow users to view progress per set without duplicating the game

• Possibly introduce different badges to indicate the presence of multiple sets

• Surface multi-set achievements consistently across:

  • Game details

  • Pause menus

  • Achievement views and stats

📦 Benefits

• Eliminates duplicate game entries for subsets

• Aligns LaunchBox with current RetroAchievements functionality

• Provides a clearer and more complete achievement overview

• Improves usability for challenge and specialty achievement sets

💡 Notes

• Base set behavior should remain unchanged

• Subset visibility could be toggleable per game or globally

• This builds on existing RetroAchievements integration