Okay, let's go over everything that's wrong with this.
• First, no description to explain the controls; players have to trial-and-error their way into finding out what does what.
• Going to the menu screen and clicking "Information", one would expect to get actual gameplay information... not about how this was a school project for "Class 7-B" or whatever...
• ...and that most crucial part of the game is in Russian, no less.
• The arrow keys that control the game... also scroll the browser page. (Reason #1 why WASD has become the modern standard.)
• Speaking of, LMB to fire your gun? Incredibly unintuitive, since it's the player's natural instinct to use their right hand—their primary mouse hand—to press the arrow keys to MOVE. (Reason #2 why WASD has become the modern standard, , especially for games that require the mouse.)
• The corridors in the game are almost too narrow to navigate, and you'll often find yourself bumping into corners or completely missing your turn. There's no reason horizontal corridors have to be half as wide as vertical ones other than willfully frustrating the player.
• For what little UI there is, it's incredibly cluttered. I have no idea what "50 10" in the top-right corner is supposed to mean, and the "save" and "Menu" buttons (yes, capitalized differently like that in-game) are maybe too close together.
I could go on and on, but I'm not even sure you can read this, and I'm basically just writing this for my and other people's benefit. Whatever this is, it was probably designed to just be a class project and not really meant for public consumption... but if this is what you show your teacher, I would not expect a passing grade if I were you.