DOJ chaining is extremely brutal and restrictive ultimately in terms of player creativity. It's a very memorization heavy game, more than the average even for CAVE, and while I find the music and visuals attractive, I don't consider it a great game. You will notice that all the good runs of DOJ out there look even more samey across the player base than for other shmups, because there is such a thing as singular way of playing it that dictates every moment you will use shots, every moments you will use laser and every pixel you're moving your ship to from beginning to end.