1) I definitely noticed that the game is a demo, based on the fact that the file name is "Demo".
2) How would I or anyone else know that the full game is available in Steam when you have not shared that information anywhere on this page?
3) Saying "you can play the game without bugs if you give me money" is the same as saying "I couldn't be bothered to present my best work in the demo, but maybe the version you pay for will be better". This is consistent with my comment that you did not seem to have put real work into the project.
4) I looked it up, and while your "game" has several positive reviews, many seemed to have popped up quite recently (around when I put out my review). Most of them are in Russian, and when translated it seems that people just said what the game is and gave you a thumbs up (not an actual review). Two of the reviews are almost identical (one in English and one in Russian), and two of them literally say your game is trash or that it's not worth the money, yet they still gave you a thumbs up. This suggests to me that some of the reviewers may have been paid for, or were trolling you.
Based on all of the above, I've adjusted my review to one star. Terrible game.