Very nice episode. It very much felt like Treats, with a mix of Gary Takes A Bath, but with elements of Pourous Pockets and Dumped. My thoughts:
Da Good
-The episode was genuinely funny throughout. Many scenes worked very well.
-I loved how the episode was nothing but Spongebob and Gary (and that one part with Patrick). I think it really shows the strength of the characters, seeing as how the episode was pretty much Tom Kenny talking to himself. :p
-The part where Spongebob is alone under the chair was a Pre-Movie esque scene. Very smartly written.
-I lol'd when Patrick referred to Gary as "Gareth". Dunno why, that part just got to me.
-I also loved Gary's rampant obsessiveness over the ball-I like that character trait in him.
-Spongebob's Alarm gag was also pretty funny.
Da Bad
-The part at the store with Patrick's brain wasn't very funny and kinda felt Season 6-ish.
Otherwise, this was a really good episode. 8.5-9.0/10. Good.