It was awesome. One of the best, amazing tv series I ever saw. It had action, adventure, mystery, and comedy. I liked how it stuck to one summer unlike phineus and ferb. I just loved how they displayed bill cipher and his comedic character while still displaying terror. Alex Hirsch, if you are reading this, you did an awesome job, one of the best series I ever watches.
P.S. Can you make a sequel to this where bill comes back in another form or perhaps another villain, I just can't get enough of the mystery twins in two seasons