There are five Call of Duty games on DS, released in this order: Modern Warfare -> World at War -> Modern Warfare 2 Mobilized -> Black Ops -> Modern Warfare 3 Defiance. None is a port, they are all spin-offs with exclusive missions, characters and plot... not that I remember any of it.
The first three games use the touchscreen for aiming, and needless to say emulating them on PC with mouselook absolutely trivializes them. The last two use the front buttons for camera input, which I used to find a poor substitute for a real right stick but is actually a solid workaround: graphics aside the modern control scheme makes them feel like they could have been released yesterday.
I like observing a series as it gets better over time, and this is a case study. As you progress through the series you get more and more complex environments, detailed allies and enemies, distant scenery, elaborate reload animations with moving parts, loud weapons with heavy recoil, myriads of level-specific assets, and of course over-the-top scripted events with vehicle chases, destructrible environments and first-person cutscenes. The whole chest-thumping Call of Duty formula, now in cutesy 256x192.
Regarding the level design: expect no miracle, it's still a bunch of corridor shooters, and a pocket version at that. The mission complexity is near zero.
Verdict: 2 nightshifts out of 4. Oh yeah, because I forgot to mention, they are between 2 and 4 hours each. My fault for expecting them to last me a week.
