Technically, there was more than one spider...

 Lavalantula

Yep, found your problem right there....

        While stuck in traffic on his way home from being fired off the set of a future theatrical bomb, a volcano erupts and a spider that violates everything known about lava begins it's reign of terror by scaring the bajeepers out of our sad, sad protagonist. Yes, we have a Sharknado clone and Fin makes a cameo to reinforce that sad fact.

IT'S BRO-TIME, BRAH!!!

        Steve Gutenberg trying his best to be a badass. Nobody's buying it, Mahoney!!! Oh look...you threw a Michael Winslow a bone!  Don't get me wrong, he's being self-depreciating, and it's just adorbs. Making fun of his washed-up career by playing a washed up actor. 

        Look, we've seen these movies before (or at least I have...a lot).  There's nothing really new here other than the storyline and cast. It's Hail Marys and pseudo science with a LOT of bad acting and questionable CGI. It's a movie best watched hungover on a late January Saturday or Sunday afternoon. The spiders look decent, but it's no Industrial Light & Magic. The acting is...well...it has Gutenberg, Winslow, and Peeples. You tell me what happens when put those three in the same film.

So to summarize:

Steve Gutenberg playing Geve Stutenberg!

Nia People's veiny cleavage!

Patrick Renna looking almost exactly like he did 30 years ago with an ever-so punchable face!

Seriously, I wanna to punch him in his weird face.

Saturday: Most people prefer gummies to cookies....