I've been playing
Scribblenauts if you don't already know.
Premise: You are presented with 10 worlds. Each world has 10 puzzle stages and 10 action stages. The goal of every stage is the same: Get the "Starite" piece. In puzzle stages, you must complete an objective in order for it to appear. On the other hand, action stages show you the Starite and you simply have to reach it.
Novelty: You have a notepad that allows you to summon items to assist you. Practically anything you can imagine, you can create. There are exceptions such as no copyrighted things, no places, and nothing adult-oriented (anything relating to alcohol/drugs/sex). It mainly supports nouns, but there are instances that are used.
Other: You are graded on your performance at the end of each stage and awarded "Merits" (achievements) and "Ollars" (money). Merits don't do anything but have amusing names and provide a sense of accomplishment. For example, solving a stage using completely new items will earn you the "All New!" Merit. Ollars can be used to by more avatars, music tracks and unlock the other 9 worlds (only 1 comes unlocked when you start). You can complete each stage any number of times and can earn Merits and Ollars each time.
Why I'm still playing it: Besides the fact that trying to stump the game is fun and interesting, completing a stage only earns you a silver star for that level. In order to get a gold star, you need to complete it again 3 more times in succession with each successive time using items you did not use in the previous trial. So basically the 200 stages of the game are quadrupled. In addition to that, the levels themselves are not always so straightforward and a lot pose significant challenge, even with the godly ability to create anything.
Overall rating: 9.9/10
I'm only deducting that 0.1 because the movement controls are a little bit wonky, but as a whole, it's an amazing game. It almost warrants buying a DS just to play it.
Words that do not work:
-crypt
-colony
-eclipse (solar/lunar)
-pauldron(s)
-moai