I remembered that I had problem with the Alien campaign and eventually leave it alone, but now, after trying to pass the first level and 30 minutes I'm truly feeling dizzy. I'm the only one with a similar problem ?

You are not the only one. I started playing as the Xenomorph and I got nauseated. Not the better faction to start with I'm thinking.

Same here. The fisheye view is not the most pleasent. Running at high speed feels ok to me (MP) but SP is slower and feels worse. Still a very interesting campaign, but it can be annoying.

Yeah, the marines and predators missions don't give me dizziness. Something tell me I'll avoid the Xenomorph except for making (Very corrosives) rugs

I can tell you from experience that you get used to it. The fisheye perspective exists because the FOV is actually 125%, which is a distinct advantage over preds and marines.

Moving quickly and unconventionally is absolutely essential for the alien. If you think that's disorienting, check out this part of a 1v1 video I made yesterday (me as alien vs. digital-ASMODEUS as minigunner). https://www.youtube.com/watch?v=NlthzvncRz0#t-5m10s

LOL, showoff :P
Good movement, though. What gives you those sudden bursts of speed, one of the trick jumps? How many of those do you use?

I crouch-jump like a motherfucker. In fact, I stay nearly crouched all the time. Not only does it make me about a third the size, but crouch-jumping when aiming yourself upwards gives you much more speed and distance than regular jumping. Strafe-running is also faster than regular running. Combining the two is the most basic way to increase your speed. I don't recommend leaving this on permanently, but you can explore toggling crouchmode on and off by going to the console, deleting SAY, typing in CROUCHMODE 1, re-typing SAY and pressing Enter (doing the same with CROUCHMODE 0 will change it back). This will make the crouch button a toggle rather than depending on holding it down.

There are also advanced techniques that gives you nearly untouchable speed. These are imo imperative for players who want to win with the bug. Obviously, the minigun will tear you apart in literally less than half a second so you need all the speed you can get.

I have a whole video demonstrating these techniques and showing how do them: https://www.youtube.com/watch?v=Q-cslGY0_DQ

I'm thinking of making a proper guide for the alien. Do you think that would be of any use? If so, does anyone have any suggested questions I would answer? I've been told my "how to play as the alien" tutorial starts off immediately with the more advanced stuff, which, looking back on it, I admit is pretty true.

Absolutely yes.
Predator and marine guide would be useful too

Go for it! I think the most helpful thing for an Alien is knowing which fights you can win and which you should run away from. Stuff like what do you do with 3 marines in a corner with flares everywhere and miniguns ready? What's the best area of a map to fight a predator if he's using the speargun? If you see a predator and a marine fighting, who do you go for first? You could also talk about which levels are best for Aliens in general and stuff like that.

While I'm probably not the target audience, I know that I would never bother with a pure video guide. It's just too annoying to jump between sections in a video, you can't easily repeat a section and pausing doesn't let you see anything but a still image.

Purely written guides do have the issue that visualizing certain techniques can be hard.

IMO the best one would be a written guide with one or more short videos demonstrating very specific things.

Is there any way to increase the brightness in the game? Especially with aliens dark maps are a pain. And unfortunately the game has way too many dark maps.
I would prefer a written one. The videos I've already watched, well done. Thanks!

The flares in that video are much brighter than mine. Any trick to get them brighter?

Edit: Sorry, I initially replied to the wrong post.

Yeah. Pause the game and look under video settings. Turn the gamma all the way up. That's how I have it set.

I think that might just be a result from the recording software that player used. There aren't any tricks to making the flares themselves brighter. Although if you turn up the gamma, the entire game will appear brighter.

Gamma is already at max. But that leads to too much contrast. I rather need the opposite, less contrast and more brightness.