Kaiju Alpha Controls

Read from the official description:

Every key

KeyActionNotes
1Skill 1Usually the basic melee — a bite or a claw swipe.
2Skill 2
3Skill 3
4Skill 4
5Skill 5The ultimate slot. On Kiryu this is Absolute Zero Cannon, which Update 45 pushed to 3,750 max damage on a 100-second cooldown.
RRoar 1The stationary roar.
TRoar 2The moving roar.

Mobile and console

On phones and tablets the same five skills appear as buttons along the bottom of the screen, and a basic attack fires on tap. The number keys are the PC substitute for those buttons, not a separate set of moves.

What a roar actually costs you

Attacks cannot be performed during a roar. That is the whole trade: a roar is a few seconds where you are visible, stationary or moving in a straight line, and unable to hit back. In a crowded Tokyo server that is long enough to lose a fight you were winning.

"What happens if you roar in Kaiju Alpha" is one of the most searched questions about this game, and the honest answer is that nothing mechanical happens — no buff, no debuff, no aggro. It is a taunt with a real cost.

So roar when you have won, not when you are winning. The exception is the quiet islands — the Forest and Thailand exist partly so that people can roar without paying for it.

Skill 5 is not a rotation button

Slot five holds the ultimate, and Update 45 made that literal for at least one kaiju. Kiryu's Absolute Zero Cannon now hits for up to 3,750 but sits on a 100-second cooldown, up from 44. On a body like that, pressing 5 speculatively is the difference between winning a fight and standing in one for a minute and a half with four skills.

Which stats you raise changes how the keys feel too — Charge Regeneration is what shortens the dead air between casts. That is on the skill points page.