Robin Hood Legend Quest - C64 Longplay (almost)

Gameplay begins at 00:29. Unfortunately I couldn't finish the game, because I couldn't find the eighth red ruby (see 42:05) even after backtracking the whole world that was available at the end. I also forgot at least one key, the one at 5:10 on the left, which only makes the wall to the right of the key disappear. Perhaps it's mandatory to find all keys so that you can find the eighth red ruby, even if the forgotten key unlocks a passage that is not absolutely necessary to play through the game. Furthermore, I noticed these bugs: Some bat sprites are corrupted and the sprite collision detection with the blue balls did not work. Since I don't want to deal with this game and all the bugs anymore and search for the lost red ruby even longer, I publish the result of my work here as an "almost longplay". BMC64 (RasPi 3 B+) HDMI capture at 720p/50Hz. Snapshots were used for this video.