I beg to differ - this was a realy great episode!
First of all, I like it exactly because it was oldschool. Remember, this is what caught all the AT fans in the first place.

Even though it's "just" a Susan episode, man, this was really, really great.
Also VERY creepy at some points. Creepy like Lemongrab-episodes-are-pretty-normal creepy. The voices, mutants, atmosphere of insanity and sadness…

Don't worry, if the Lich was actually in control, he wouldn't wait. He would just start the destruction - he's a machine set to kill. He doesn't wait and watch how things develop.

Yet he thought it was Finn who started the fire. Also, we will never know how did Jake heal so quickly the second after he exited the screen…

Gosh, you're right! Didn't realise that… :D

I loved it! The cutesy wootsy atmosphere being torn apart in a split second when the Lich got through… perfect.
Also, this means Sweet P and Lich share memories and in a way, the Lich stood up to protect Sweet P when he was cornered. Lich doing something nice!

I believed her! I never doubt PB, she's the only mature and reasonable person in Ooo and keeps it that way even if it means people will think she is a buzzkill. If she says something that doesn't make sense, it's usually because she knows more than others and doesn't think it's important to explain.
I have to respect…

Yeah, especially loved the voice acting. Now both my favourite Californication girls took a part in Adventure Time - how cool is that!
I loved Becca and Marcy.

I'm still 2 reruns behind you, but I tots agree bro. Or sis, can't really tell. *Timmmmiiiieee*

No no, season 7 is already announced.

Slimy-D as in Slim Sha-D-y, maybe…?

No no, reset seems like a very appropriate word. And it connects nicely to the end of The Cooler where she realises her ways may need a bit of reconsidering.

I'll just leave this here:
1. Episode Breezy - Vision of PB singing "My hero arise, let love be your guide", holding the Finnsword
2. Episode Is That You - Finnsword actually appears
3. And now Pajama Wars

Let me think aloud for a minute here. The Finn Sword was in the Breezy episode. When Finn saw PB, her phrase was "My hero arise, let love be your guide". Maybe Finn is about to finally hit it off with PB.