Adding new face sprites to hud?

[Astro]

Hey. I'm wondering how can i add a new sprite for the face in hud.

For example, grittin teeth when a player fires the weapon for more than 2 seconds and has the invulnerability on.

[Biz!]

The first step is to replace the sprite

[Darch]

You mean grittin teeth + invulnerability eyes? That would require extra frames. As far as I know, you can't add frames, only replace the existing ones.