questions about RNG to explore:

• how does the game calculate RNG?
• enemy movement is influenced by the player position, but what effect does RNG have on it, if any?
• enemy spawns seem to have fixed locations, but the number of enemies which spawn (and when) seem to be random
• when enemies shoot seems to be random, but sometimes an enemy seems to get priority---it shoots 3-5 bullets at once. something to do with the sprite order?
• the fortresses at the ends of areas seem to have a timer before they stop spawning enemies. is it a fixed timer? what determines its duration?
• is an RNG manip run possible outside TAS? the power-on pattern seems amenable to such a thing