Now that I've played the three games I mentioned above, let me talk about them.
Elite Beat Agents- Unless you are a huge perfectionist OR you have a lot of friends who also own this game, I wouldn't buy this game for any more than $25. Allow me to explain: while the game lasts, it is one of the purest shots of the element FUNIUM I have ever received. The music selection is incredibly spotty, but even the songs I absolutely hate are a blast to play. The problem comes when you either beat the game or get stuck on the last stage, 'Jumpin Jack Flash', which sends most mortals into paroxysms of terror and frustration. Assuming you manage to beat the game, you can play through it again on harder difficulties to unlock bonus stages or for bragging rights. Assuming you get stuck on the last stage, and no matter how hard you try you are only human god dammnit, why did they make it so fucking hard it's like twice as hard as all the other levels even on the easy difficulty it's ridiculous...sorry, what was I saying?? Well, at some point unless you have friends to play the game with--I'm told the multiplayer is quite rich and addictive--the game becomes a $25 accessory, perhaps something you revisit once a year to remember the good times. What I'm trying to say is, this isn't a game in the vein of Tetris or a Mario title: casual titles, to be sure, but ones you can play over and over without getting bored or frustrated.
Contact- Having blown through this game in 15 hours or so by using a FAQ, I can safely say that it is not an easy recommendation. There's a lot to say, so bear with me. I, personally, loved the game, and will probably play through it again, this time at a more leisurely pace to squeeze all the juice out of it. However even as an admitted fan of the game, I would want to craft my own custom warning label to sit next to the ESRB one. For starters, the game is vague to a fault. Not only did the main story of the game never get satisfactorily fleshed out, but playing the game itself is a series of "what the fuck am I supposed to do now??" segments that remind me of mid 90s PC point-and-click adventure games. One part of Contact, tucked nearly at the end, has you going to a mini-island because the final dungeon is covered by a storm. This storm is created by one of the villains using a keyboard on this mini-island. In order to get rid of the storm, you need to go buy a piece of music from one of the characters in the game for 10,000 gold. I should add that money is extremely hard to come by in this game, so you can either kill this character over and over until he drops the item, or you can find/buy/cook some sushi and give it to the mayor of another island, though you're not given any indication that we would give you 10,000 gold for it until you open up your menu afterward and see the increase in funds.
The other big problem with the game is the various parts of the gameplay system that could have used some substantial time expedience. Cooking things in the game is all but a necessity unless you want to keep spending too much money on potions. However, every time you make a dish you have to manually select the ingredients, manually select to combine the two, and then wait for a cooking animation to complete or fail. This wouldn't be so bad if you didn't often go to dungeons where it's suicide not to have 30 or more potions. If you could just cook multiple items at once, the game would take maybe 1/3 as long. What's more, one of the ingredients of a potion is water. You can get water for practically free by buying bottles and filling them up from various wells in the game. Of course you can only fill one at a time, so you'll spend too much time hammering on the A button so your character will fill up all the bottles. I hate it when games give you the chance to be smart and save money by making items yourself, but all the time you waste cooking/filling up water you could just as easily spend grinding enemies to get money to go buy potions.
Lastly, the game is far too short to justify so many choices. The skill/stat building system is based off the Morrowind/Oblivion mold, so the more you use skills/stats, the better they become. In practice, this means that you are better off focusing on one weapon type and one or two of the game's 'costumes.' This could provide some incentive to replay the game, except that there are many times throughout the game that you will have to painfully backtrack to equip the Shadow Thief costume to unlock doors/chests. What's more, you don't ever need to bother with any weapons other than what you find or the game gives you. One of the early bosses drops a sword that does +50% damage against human enemies, and this is something so powerful I used it on the last series of bosses to great effect. It's too bad the game either wasn't longer, or didn't force you to use each weapon type/costume on the different islands. As much as I like choice, I also like feeling that everything in a game has a purpose.
Anyway, it's a fun, offbeat, weird action/RPG that will be unlike anything you've played before.
Dragon Quest Heroes: Rocket Slime- For the first couple hours of this game, it's a childishly easy 2D overhead platformer with a fun twist (you need to rescue 100 slimes, and as you do the game's main town grows and repairs itself). But then you start getting to the serious tank battles, and it becomes a frantic, fantastic action game that demands you pay close attention to various factors at once. More than once both tanks were down to O HP and I was frantically trying to smash the enemy tank's heart before they got to mine. I don't find Rocket Slime's platforming/exploration stages to be tedious or pointless, but the tank battles are where the game's true juice lies. I was reluctant to buy this game for even the $20 I snagged it for, but this is one of those times where you can trust the reviews. Rocket Slime is one of the best games for the DS, and the fact that there are numerous references to Dragon Quest VIII (I practically leaped for joy when you get an oaken club and it has a description delivered in Yangus's unique speech pattern) is like fanboy icing even for someone who isn't a fanboy of the Dragon Quest series. I would also go so far as to say that it's one of the best translated games on the DS, because the game's constant puns and wordplay are both cute and irritatingly frequent. They were REALLY going for a certain tone and feel to this game, and absolutely nailed it. I particularly love the blue eyed gaijin-style ninja slime, who is in a trio with two more 'traditional' Japanese ninja slimes, and speaks with a ridiculously over the top surfer slang American accent.