Sonic the Hedgehog 2 v0.9.11

Corrects behavior across Knuckles presentation, save menus, widescreen backgrounds and special-stage saves.

• Restore original Knuckles title/HUD/monitor artwork and hurt, death, ledge and glide-landing behavior, including EHZ2 boss-floor landing.
• Keep donor characters behind results text and countdown digits while preserving normal priority terrain.
• Correct save-menu start feedback, departure presentation and character/counter details.
• Correct the qualified attract-fade, left-edge background and title-card presentation cases.
• Preserve ordinary gameplay and menu proportions through native special-stage entry and return. Special-stage saves wait for a complete track, including fresh-process reloads.
• Accept Steam .68k ROM images and retain the established launcher settings behavior.

Fresh installs continue to enable adaptive widescreen Fit to screen; existing explicit choices and native in-game saves are preserved. Quicksaves are specific to the exact build. Supply your own supported Sonic 2 ROM and any optional donor images; no ROM data is included.

Original special-stage percussion and the white fade remain unchanged. Larger parties and donor actors retain original-rate motion under high refresh mode.

Validation includes focused correctness tests, current-build save/load, replay and rollback, source-pixel and recorded-route checks, representative shared-engine consumer checks and packaged dependency/defaults checks. Validation remains bounded to the tested configurations.

An existing framework watchdog can eventually abort a very long native pause. The same failure was reproduced in v0.9.10; it is tracked separately and is not claimed fixed here.