PP doesn't seem to work right, or maybe I'm just not understanding how to get it. Completed the game once and the challenge mode #1 with an SS and only had twenty PP to show for it. Considering the cost for an HP upgrade is 100, that seems steep for beating the entire level and still not having the funds to get even one upgrade. Though, in truth, a reduction of multiplier lost when taking damage would be vastly useful to HP max anyhow, since I found myself constantly dying intentionally to try for a different weapon (the icon that upgrades your weapon to a new type doesn't change, so there is no way for me to collect the type I desire. I assume it is supposed to swap through the letter corresponding to the weapon type like in classic R-Type / Gradius style shmups but it always displays an N or H, not sure which it is).