I've been and it's an awesome little town and very much picture-worthy! I went when my friend was studying abroad at Göteborgs Universitet (University of Gothenburg). I'll give you some pointers on this city and Liseburg later tonight.
I was going to do a trip report to Liseberg but I feel it's pointless for a couple of reasons. 1. It would take forever. Mainly, because there is no American equivalent. 2. Very few people reading this site will ever find themselves in Sweden, let alone Gothenburg. That being said, if you ever find yourself in Sweden, you should go. It's a great park and you can spend the whole day there with plenty to do.
I'll just take a few minutes to write about Helix, Balder, and Kanonen.
Words cannot describe how great Helix is. I'm not sure I've ever ridden any Mack rides (at least to my knowledge). It's fast. It's smooth. And it's super lengthy. This ride does not let up from start to finish and every part, every drop, every inversion is picture perfect. On top of all that, it's designed to move a large capacity of people very quickly - my average wait was 30 minutes during a modestly packed Saturday. The best way to describe the whole experience is to say, Helix gets right everything Sky Rush gets wrong - down to the lap restraints. My only complaint is the music in the queue is insanely loud and annoying. My takeaway is this: we need one of these, stateside. It's a revolutionary experience.
Tip: I rode Helix from the front, middle, and back. The front is definitely the better ride.
Balder. Best wooden rollercoaster I've ever been on. SO MUCH AIRTIME. The first drop gives me butterflies just thinking about it. The middle section is the better seat on this one, maximizing the air time over hills.
Kanonen is a standard Intamin offering in a very tight location. The whole ride is maybe a minute long and, similar to say Fahrenheit at HP, the ride capacity is terrible. However, and maybe this is something to note for the future when it comes to Intamin rides, this little coaster packs a lot punch in 60 seconds. I would have jumped on it again and again if the line didn't move at a snails pace.
Check out the pictures! And if you have any questions, I'll try to answer them to the best of my ability.
Here's an updated POV posted by the park. It displays some fun facts while the train moves throughout the course. It's also not as dreary outside as it is in the original video and all the trees are green.