Before you start complaining about the plot being flawed - take a few minutes to think..
The human military is very diversed - ranging from AH-64 Apache to Leopard 2 and F-22 Raptor. Why do you think the Ceph would be limited to using only one type of flyer unit (from C1) having in mind IT FAILED BIG TIME IN C1 SINCE THEY EVENTUALLY FAILED TO WIN AGAINST US NAVY. The tank, helicopter or interceptor is not a human - it is a machine/unit operated by men. The same goes for aliens. They use different type of machines. The units you see in C1 and C2 are not aliens. These are machines operated by aliens inside.. Come on, how can't you see it people.

The actual alien without machinery: HERE
You see, he's very similar to terran amphibians - for example the octopus. It seems obvious these creatures must have evolved in ocean (it was mentioned in C2 anyway).
Now take a look at unit from C2: HERE
Have you noticed the tentacles on the back of the unit? Now try to compare it to alien from C1. Yes, they are very similar. It is just that you fight aliens in exoskeletons in Crysis 2. Since they are amphibians their natural environment would be some kind of liquid (water or not) and they don't have legs. That's why they use these exoskeletons - how else could they fight? Flying units are not your dream unit for invasion - they can't take cover, they are easy target. Isn't it obvious you need infantry to win?

All in all I think that aliens from Crysis 1 are pretty well connected to aliens from Crysis 2. The only thing that cannot be explained is that: Since they are so technically advanced that they came here 2 milion years before humans from the galaxy M33 that is 3million light years away from us - they would probably already have such a technology that they would wipe us out without any problem nor casualities on their side in a blink of an eye. But hey, it's a game, it's not suppoused to be 100% realistic..

Spread the word, haters.

The only thing that cannot be explained is that: Since they are so technically advanced that they came here 2 milion years before humans from the galaxy M33 that is 3million light years away from us - they would probably already have such a technology that they would wipe us out without any problem nor casualities on their side in a blink of an eye.

Well they do (did) have anti-gravity technology, intergalactic space travel, gravity 'bombs', rapid freezing, the ability to drain power, etc technology but all that has disappeared even though it proved effective in Crysis. The Ice Sphere denied the entire island to humans, why would they stop using it in favour of biological weapons?

Hargreave talks about the Ceph wanting to reduce the impact on the environment but freezing everyone would do a better job than giving them some disease that melts them. If you took every human on the planet and broke them down into slop all kinds of diseases would be created.

There are massive plot holes and I wouldnt bother wasting your time trying to make sense of them. For instance, the Ceph in Crysis 1 clearly crashed on Earth in their ship. But in Crysis 2 they are apparently everywhere.

Did multiple ships crash? (unlikely)
Did one ship crash and then they spread out? (possibly but then why do they look different?)
Were they here all along? (then whats with the crashed ship and signal to space?)

It is possible the red things are not the Ceph at all and are actually created by the Ceph (the blue guys) as drones to fight for them.

they were here all along. the ship found was a ship that had crashed, possibly sent to investigate why the Ceph on this planet didn't communicate anymore

There are massive plot holes and I wouldnt bother wasting your time trying to make sense of them. For instance, the Ceph in Crysis 1 clearly crashed on Earth in their ship. But in Crysis 2 they are apparently everywhere.

Did multiple ships crash? (unlikely)
Did one ship crash and then they spread out? (possibly but then why do they look different?)
Were they here all along? (then whats with the crashed ship and signal to space?)

It is possible the red things are not the Ceph at all and are actually created by the Ceph (the blue guys) as drones to fight for them.

I think that these aren't plotholes, but rather parts you have to think about yourself alone. I find it better than if everything was obvious. Nowadays there are more and more games/movies in which there's only one truth that is obvious and you understand everything from the very beginning. If you'd put man from for example 1000 BCE into our "world"/society - he wouldn't understand anything. He would consider us godlike. Now think about that these aliens predate human race 2 MILLION years. Sh1t just got real, huh?

I think that from this perspective you literally shouldn't understand what are their motives and intentions nor what are they doing on earth and why did they wait so long. You only know that they're hostile and you have to fight back. Really, this plot is, at least in my opinion, far better than many movies' and games' plots.

CEPH have evolved, as you said crysis 1 CEPH have been here for 2 million years so the CEPH who came from their planet have evolved like humans who evolved from apes

they would probably already have such a technology that they would wipe us out without any problem nor casualities on their side in a blink of an eye.


they are wiping us out , with that plague. there are 2 possibiltys
1. They are testing the plague in NY area, cuz only that area is infected, and later spread all over the world
2. They only want to kill humans in NY area

1. is more plausible.
they are killing us without destroying earth and they somehow use the stuff that humans turn to