For the average player, v1.5d feels like a refinement—enemies are slightly fairer, and the Marksman is usable again. However, for the —the P-rank speedrunners, the Brutal-difficulty masochists, and the Cybergrind endless warriors— v1.5d is essential .
Completing levels under strict limits (e.g., under 4:30 for 1-1: Heart of the Sunrise). Kills: Eliminating every mandatory enemy on the main path.