The RNG in this game is controlled by the behaviour of certain enemies. For the first two worlds, there are 3 enemies that change the RNG, the green ghost, the white ghost that teleports, and the pink enemy with the open mouth that charges at you.

The green ghost only changes the RNG when he switches direction(eg. Horizontal to Vertical), the white ghost changes it while he is walking (every two tiles or so?) and when he faces a different direction, and the pink enemy changes it when he bumps into something, but only when he is not in attack mode (when Bomberman is not on the same horizontal or vertical plane.) Also, whenever an RNG enemy is trapped on all four sides by a block, the RNG will change every single frame.

For reference, here’s a fully manipped route I made for the first two worlds, with the RNG values on the upper left (03D8,03D9,03DA.) I just used one of the mashing seeds for convenience, this could be optimized much more. Bombing the door also changes the RNG, I do that in 1-1 to make 1-3 easier to deal with. You can extend the manip into world 3, but it gets trickier after 3-1. More RNG enemies, and more chances for an RNG enemy to be trapped.