In some ways, an improvement on the first Runaway game, in others, it's not as good. If you enjoyed the first game, I'd pick this one up for sure, but I probably wouldn't recommend approaching it without. The first half of the game is set in beautiful tropics and the colour and art is actually really nice. Some... interesting writing and a few annoying puzzles, but the last half hour will be some of the most frustrating that you will have ever experienced.
It is probably best as a buffer between Runaway: A Road Adventure and Runaway: A Twist of Fate, but if you like Pendulo adventures, this is clearly one.