It’s not, strictly speaking, a goo. From Glory To Goo’s enemy isn’t a sinister gunge, but that minor disappointment didn’t last long.
Its monsters are individual, blobby little (mostly) purple nasties, but they act as a flood anyway, taking great exception to your base and the resources it pipes back and forth (much like in Creeper World), but coming mostly in waves like They Are Billions. But the thing with FGTG is that there’s always a little bit more to deal with than you think.