works on vba-v24m-svn-r422.
We can go debug mode, when we use an item called "なし"(nothing). it can lead to make the game finished in 6min.
You can go ending credit, when you choose "4. MORIテスト"(MORI Test). You can warp anywhere you want, when you choose "2. ひぐち テスト"(Higuchi Test).
In any way, the graphics of the field are broken. and it's not broken in real GB console.