Wario Land: Shake It! (WL:SI). It's the game that makes you realize how greedy you are. The game is decent and fairly enjoyable. Even when I was annoyed playing levels over again, my negative feelings quickly melted away replaced by the simple satisfaction of playing with tight controls tuned to the mostly familiar yet still interesting level design.

The Controls

The responsiveness and precision of the NES style controls are very similar to the old school Mega Man controls. Wario's DASH attack is similar to Mega Man's slide while both of their JUMP mechanics are very similar in their directness using a single button input.
The motion controls are thoughtfully and carefully integrated. Wario can only SHAKE things up (coin bags, enemies, bosses, and cages) when he's standing still. Because the player doens't have to worry about moving around while SHAKEing, they are free to get a firm grip on both ends of the Wiimote and give it all they've got. Furthermore, the two handed form Wario takes on for SHAKEing objects is reflected in the way the Wiimote is griped in both of the player's hands. For this reason, a correlation is created between how hard the player shakes the Wiimote, and how hard Wario SHAKEs the object in his hands.
In the same way the SHAKE motion controls were integrated comfortably into the core design, the GROUND POUND and SPIN (while hanging on a bar) are designed to be used when the player isn't moving via the D-pad. Designing the game so that the conflicting controller states never coexist is very smart.
Holding the Wiimote NES style can do wonders for simplifying gameplay. Without so many buttons to worry about, games tend to be designed with less interface complexities that usually transfers into the core design of the game. The biggest draw back to using the Wiimote in this way is the lost of the analog stick for analog controls.
Fortunately, the developers of WL:SI have added analog functionally into the game via motion controls. When traveling underwater in the Subwarine, boosting around in the jet pod, or zipping around in the cable riding cart the game smoothl controls using motion controls like a two handed analog wheel.
Furthermore, objects and cannons can be aimed using the same tilt motion controls. In these cases, the player can determine the starting angle they want to aim at by tilting the controller at that angle ahead of time. In Yoshi's Island for the SNES or DS, players had a limited number of starting points in which they could aim their eggs. Using motion controls, Wario has possibly found a next gen way for 2D aiming using a single D-pad.

The Level Design

The folded level design is back, and it may be even better designed than Wario Land 4 for the GBA. Players trek deep into each level at their own pace solving puzzles, nabbing loot, and taking note of the surroundings. Once players reach the captured Merfle, the crease, the player must make haste to escape back to the beginning of the level in time. Looters are notorious for folded level design like experiences. It's the old Indiana Jones design after all.
On the way out of the level, the game turns into a sort of Sonic style speed running game. Small mechanic boxes that Wario manages to shove himself into, power Wario up and propel him forward at high speeds. While in this super fast running state, Wario can knock out all enemies in his path, run on water, super slide like a pro baseball player, jump really far, and crash through metal blockades. As long as Wario doesn't run into a wall, get hit by a projectile, or grab onto a rope, players can make their way back through a level in a unique and speedy way. For these reasons, this SPEED RUN mechanic is a well designed powerup.
Unfortunately, Wario travels too quickly for the screen size/scroll speed to effectively show what's coming up next. Like in the Genesis Sonic games, doing well at high speeds requires a lot of level memorization (at least a lot more than Super Mario Brothers which has next to none). The game really should zoom out when Wario is in the SPEED RUN power up state so players can look before they leap. To try and remedy this visual problem, there are arrows, coins, and other visual clues that tell players when and how to jump to be successful. It's a design crutch, but it's better than nothing. Fortunately, just before the crease in the folded levels players can activate a check point and reset to that point if they mess up. This feature takes a lot of the redundancy and frustration out of the game.
Ultimately, the enemies don't have enough contrary motion and interplay. For these reasons, the game lacks a significant amount of counterpoint. The base 2 enemies in the game aren't even technically enemies. They move around like Goomba but they can't hurt Wario at all. Furthermore, even if the enemies were designed to be more threatening or influential in the core design, Wario (like Link) has hearts that allow him to sustain many hits of damage. To further diminish the role of enemies within the core design, players can purchase additional hearts to adjust the difficulty of their experience. Unlike Mega Man 9 where the adjustable difficulty options have decay, transform the challenges in the levels, and must be executed by the player, adding hearts to Wario's overall health doesn't really change the nature of the challenge at all. In other words, being able to take more hits doesn't affect the thing that's hitting you. In these ways, WL:SI lacks dynamics.
Because dying is unstressed in the core design due to the enemy design , WL:SI is more focused on its platforming and puzzle elements. One of the biggest differences between Wario and Mario is that Wario is a violent, greedy brute. But what does it matter when the enemies to beat up on aren't very threathening?

Closing Comments

The graphics are phenomenal. The amount of detailed hand drawn animation that has gone into this game is astounding. I was continually impressed by the presentation.
The intro story was far too long winded for such a simple story.
Each level mixes things up with new level elements. Some are traditional like conveyor belts, while others are strange and intriguing like the 3 pronged tiling platforms in the Asia themed level.
The form fits function for some of the spiked enemies is surprisingly precise. Even during the detailed animations of a fork head enemy tumbling through the air, at every frame the fork is coded with a hit box that's ready to stab Wario.
Wario transformations (fire, crushed, snowball, and shrunken) are used fairly simply and aren't layered very deeply into the game ideas for the level. In other words, they're neat but largely forgettable.
The hidden treasure and the mission (achievements) system are an interesting way to provide extra challenges without making a hard mode or changing the levels.