Probably fixed rare bug:

the pseudo-random routine pseudo-randomly generated X,Y for new piece of food
that corresponded to immediately next snake head position.
This X,Y resulted empty when checked in the routine, but suddenly after it
is overwritten with snake head, so food simply disappears.
This leads to impossible game play, because no new pieces of food are
generated if no food is previously eaten, but there is no food to eat, so...
Hope to have fixed.

BUGS

@@ -1,2 +1 @@
-- Fix random-eaten food that prevents from playng
 - Search for proper SID song

snake.asm

@@ -342,11 +342,21 @@ genFood:
     sec                 ; if value is > 18, then subtract 18; now it
     sbc #18             ; surely is less than 18
 foodNoMod:
+    cmp #0
     bne foodNoLow       ; if it is 0, then set 1 (avoid first line)
     lda #1
 foodNoLow:
     sta calcTileY       ; use this new value as tile Y-coordinate
-    jsr calcTileMem     ; calc its address in memory
+    ; Now I have X and Y coordinate for food stored in calcTileX, calcTileY
+    ; and I must check it is not the location that I am going to overwrite
+    ; with the head in draw snake head...
+    cmp snakeY
+    bne foodOK
+    lda snakeX
+    cmp snakeX
+    beq genFood
+foodOK:
+    jsr calcTileMem     ; calc food address in memory
     lda (tileMem),y     ; check if memory is empty
     cmp #$20            ; is there a space?
     bne genFood         ; if not, must generate another number