What do I do about those … creatures?

They don't look especially friendly, do they?

It's probably sensible to avoid them as much as possible.

It seems like retreating to GIO'S is the only option.

Have a peek out the door. Have they gone?

Oh.

Hold on, maybe that MESSAGE you found in the safe might be helpful.

Soda? Why would you need to use soda?

Have you tried using a glass on the soda fountains? Maybe a drink will help you think clearly.

One of them is missing a HANDLE, though.

Luckily you found one locked up in the safe.

Attach the handle to the middle fountain. Now get a drink from there (drag the GLASS on the soda fountain).

It tastes awful and did nothing to help you think clearly. Maybe it's useful another way?

(SOLUTION FOLLOWS)

↓

Take the filled GLASS you set on the BAR, and pour the drink over the aliens.

You're free! For now.