Somewhat working first test

game/common.rpy

@@ -0,0 +1,30 @@
+# ── Rewind mechanic (shared across all scripts) ──────────────────────────────
+# Where the next rewind lands. Set this to a label string at each checkpoint.
+default checkpoint = None
+
+# Optional: a label to `call` for per-checkpoint flag resets, or None.
+# Define it like:  label .my_checkpoint_reset:  $ some_flag = False  return
+default rewind_reset_label = None
+
+# Plays the shared rewind effect, then returns to `destination` (a label string).
+# Uses `call` (not `jump`) so it is re-entrant: rewinding to a label that is
+# already on the call stack (e.g. back to a choice mid-spar) returns cleanly
+# to the caller instead of corrupting the stack.
+# Call as:  call rewind_to ".some_label"
+label rewind_to:
+    scene black
+    with dissolve
+    show screen teal_wash
+    "The world pulls back."
+    "Colour drains to teal. Sound slows to nothing."
+    hide screen teal_wash
+    scene black
+    with dissolve
+    # Run any per-checkpoint reset statements (e.g. $ rewind_used = False)
+    if rewind_reset_label is not None:
+        call expression rewind_reset_label
+    call expression checkpoint
+
+screen teal_wash():
+    zorder 20
+    add Solid("#1a4a4a") alpha 0.7