Arijigora

Ever since I remembered Hapland and posted about it, I was trying to find another game in the same vein, but I remembered it was Japanese and it had a horror theme: the middle of the screen was occupied by a nasty huge insect and some stick figures were trying to kill it and get away with their lives. It was very difficult and, like Hapland, needed a lot of thinking and synchronization, but it was very rewarding (at least, to me!).

And look, after digging in other sites etc, I managed to discover it again \o/