This video shows that the game allows the player to engage in aerial combat with an animated opponent which fires energy beams and projectiles, and also periodically teleports behind the player to smite them. In other words, Combat Initiation allows the player to participate in bona fide anime battles, therefore making it the greatest roblox game ever made. -modified text from the ultrakill wiki
You can get to the moon by using the trampolines/boosters in Stage 3 (near the towers that cannons can spawn on) because they give an absurd amount of vertical movement then use Jet Boots after you've bounced since it carries the vertical movement allowing you to get the achievement. For triple whammy get Vagabond to half health then parry him, after that he'll start to circle you, then you just spam trowel/hammer walls to interrupt him with witches brew.
To the moon: use glass houses trampolines with jet boots and bloxiade active (use jet boots when youre starting to fall and make sure bloxiade is active) Triple whammy: with RNG chances vagabond will do his sword attack 3 times, parry them all
