I'm not really sure how to categorise this one because in some ways it was quite amusing, and very fast paced, but in other ways it wavered between too easy and too hard. The story is that you are an elite bounty hunter, known as a rouge tracer or star strider, and you are sent on a mission to rescue the galactic president who has been kidnapped by an enemy race known as the Gromulans. The thing is that the Gromulans live on Earth, and the reason for this is because nobody else wanted to live on Earth so when humanity developed interstellar travel, and found other habitable planets, pretty much anybody who could afford to leave, did, and anybody who couldn't, remained. As such Earth has become the cesspit of everything bad in the Galaxy - and you have to go there.
As I said, parts of it were amusing, especially the introduction which tells you about the inhabitants of Earth. In particular, there are a group known as the Houlgans, who are divided into tribes which are distinguished by the colours of their clothes, especially scarves (direct quote). It took me a bit to click that the author was having a dig at English soccer fans, especially since I suspect that at the time of writing soccer houliganism was a big problem in England.
As mentioned, the style comes across as very fast paced. The author describes things in minimal detail and it feels as if you are moving through the adventure quite quickly. Added to this is a time bar, namely you have to complete the adventure in a certain amount of time otherwise the information that the Gromulans are trying to get out of the presidents head will have been retrieved and you will have failed in your mission. This is a new element to the gamebooks, and I find it was done quite well. It is relatively easy to get to the end of the adventure without running out of time (I took about 22 units to complete it), however when I discovered a website which contained flowcharts for these books I noted that you were able to skip large chunks. This is probably one of the few gamebooks where this is necessary.
I found it easy in the sense that you only needed one piece of information to get to the president, and this was a set of co-ordinates for a subway system (namely London's). Some have suggested that this subway maze was quite hard, however you can find a map, and once you have the map, moving through the subways is actually quite easy (and while a modern map may help, the modern map does not necessary reveal the nodes).
The hard aspect of the adventure was that there were a couple of places where there were logic puzzles, and these logic puzzles were incredibly hard. They were like guess the next number in the sequence, or guess the missing number. There was another place where you were given some information, and when it came time to use the information it was difficult to work out the instructions. I also noticed that there seems to be minimal combat, and the combat that you do have is either very easy or very hard. However, the author also makes come clever use of dice in this book, such as rolling one dice, and then rolling a second dice a couple of times and if you rolled the same number as the first, you were fried, or fell down a pit.