As the title goes.

In most of my playthrough, playing this game in a Hard intensity (represented by 4 skull icon in the options tab) really puts me on the edge due to fast movement and easy-to-kill bullet hell situation. To minimize this issues, changing the intensity to Easy (represented by 1 skull icon in the options tab) does help you a lot during the run, the "perk" itself as follows:

• High probability of getting power up before facing the First Boss (best cases, you can easily get 4/5 power ups; worst cases, 1 (or maybe 2) power ups)
• Enemy were less aggressive (slow approach, enemy's slower shoot) to you (Boss doesn't count) during the early runs
• Each time you kill the Boss, game keeps up the pacing to balance your progress during runs.
• No difference in terms of point gathering

p.s: Already confirm the strats to the mods, you can check out the confirmation here - https://www.speedrun.com/shooty_skies/thread/irasp