This review will contain spoilers!
In many sentences:
Laddertop is full of interesting ideas and some clever dialogue. I enjoyed the art style, though I found myself unable to follow who was who in the parts where the kids are in the zero g suits. Generally speaking, there are a lot of promising ideas and the story looks to be going somewhere interesting, but the book flies by so fast, and so little ultimately happens that it just leaves the reader hanging. I'm interested in reading the next volume, but for now all it has done is set up a few characters, and an interesting premise, but nothing has happened. Hopefully the later volumes are more interesting, and full of more exciting moments.
None of this is to say Laddertop is bad, it's simply too early to really tell. Hopefully the story hits its stride in the next volume. It's so easy to read, though, if the idea sounds interesting to you at all it's probably worth picking up. Otherwise, I don't recommend it.
Orson Scott Card the First Line of Laddertop
Orson Scott Card the Last Line of in Laddertop