Request Backup - it plays the animation but nothing appears. Is there supposed to be a fail chance? If not, do you think it's possible some of the units in the random list don't work?

Unfortunately, nothing happened when you play on campaign mode. because some units are removed due to stories.
and this is cannot fixable. sorry
ty for reporting.
if the happening is not on campaign mode, notice me!

I have never seen the Random Mutation skill in the available skills.

@Bak Bon Dzshow
thank you for reporting
I'll fix it.

The Penguin Rider unit has a laser attack, but you can't equip mods that improve laser weapons on it, is this intentional?

thank you for reporting, I'll fix it asap