Really feels like watching an actual episode. The voices are IMO real good, a bit interference to them which could've been cleaned up, and the levels are a bit off, but they sound fairly good nonetheless. Animations and graphics are very similar in style to the original series, which I find to a plus, I love Invader Zim.
And the story fits, too. One more thing I'd like is some more SFX, like when Gir sat on Zim and slapped him. Just looked a bit dumb without any SFX.