Like many others below me, I did not enjoy this demo. I'll tell you exactly why it is a poor game.
The tutorial text is hard to read. Please consider a different font.
Using the W/Up keys to Use the Portal and to Jump is not a good idea. In Level 2, I had placed a portal between two pillars (where the key is), and I couldn't jump to get to the key. I would recommend using another key for Use.
When a portal bullet is launched, it automatically closes an open portal. This is extra annoying when I constantly miss my shots, and I accidentally close a portal that I wanted.
I don't like that you can only use the G key to control both portal bullets. If I painstakingly open a green portal, I want to be able to open a Blue Portal, run through the green portal to grab the key, then go back through the blue portal, and then launch another blue portal to a ledge near the green portal. However, if the game were to tell me that was the "limitation" of the gun, I would be okay with it, but still would question the choice.
There is no way to know how much charge the portal bullet has. Does it have a max charge time? If so, when is that max charge time? Sometimes it felt like the bullet would go further on a shorter charge. I would recommend adding a charge meter, and maybe a "fuel" gauge so we can better prepare our shots.
Guiding the Portal Bullet is hard, and not in a challenging way. I mostly overshoot or undershoot because I don't know how long to charge it, how long it will stay in the air, and I can't guide it down when I find a good spot. Instead, I have to waste lots of shots getting where I want to go, and then risk losing that portal if I miss the follow up.
Ultimately, your attitude and disrespect towards your audience make this experience even worse. I enjoyed the ambience, sound, graphics, and physics, but I won't give you any stars for them, nor will I recommend it on Steam. Let's examine your default statement for a few reviewers:
"Already a lot of players write about the bad mechanics of the teleport. Why do you think so?"
A valid question. Some answered, others did not. I have my criticisms above.
Please also note that Newgrounds only allows us one review, and we can't respond to your responses, and I highly doubt anyone will PM you after the responses they get.
"I think the players are lazy to play games."
Of course we're lazy, we're playing Flash/Unity games on Newgrounds instead of doing important
"You want light and simple games."
Some do. Others don't. Some light and simple games are fun and good cool downs after a long day of work/school.
That said, people like to learn complex games and master them. It makes us feel awesome, and always amazes us at what people can make. That's why people love Portal, Overwatch, and others that require a different approach.
"Don't want to think and learn the game."
We want to learn the game, but pairing sloppy controls with guessing in a puzzle game leads to something we don't want to waste our time on.
"This is your problem."
It is? Goodness me, I should have known from the start it's my fault I can't play the game! I totally want to learn and support this game even more.
Instead of insulting us, take our feedback and improve your game. Or you can continue to be salty and receive poor reviews for both your games and your reputation.
Camera needs some work however was still pretty fun
Stop the camera from moving when you press left or right, make more fun levels (the 7 beta ones were really boring), fix the mechanics of the portal gun (who thought it was a good idea to make the player 'flappy-bird' the portal through a small gap in levels 6 and 7?), and add other mechanics, and this game would easily be a 5. Oh and your level 5 is broken af.