GET ON THE READY LINE, MARINES!!!
The way all the iconic elements from the films were integrated is very satisfying and brought a smile to my face. In fact, I found myself smiling a lot for all the right reasons: The tension is there as you creep forward, Pulse Rifles sound spot-on, set-pieces from the film make their way into Infestation in creative and surprising ways, the various marines have colorful personalities that evoke the Ultimate Badasses from Cameron's film, the motion tracker is brilliant at creating suspense, the way the map and flare features are highly reminiscent of the table/map thing Hudson used to locate the missing colonists in Aliens is especially inspired.
It would have been great to see some Alien 3 locales as the warm orange palette would have complemented the other locations on the Sulaco and LV-426 very nicely. It would also have been really cool if the Marines had specialties, or were class-based (though that could be tricky as it could block progression). The marines are well animated and control solidly. There is little documentation though, and it wasn't till my second playthrough that I realized you could manually reload, and that there is a cover mechanic and blind-fire system in place.
The audio was creepy and had several actual scare moments. Very surprising considering the spite-based presentation. I would have loved to have heard actual tunes from James Horner's iconic film score for Aliens though.
All in all, a great release for the DS in its final years! 2 thumbs up especially for all the fan-service. :)