Hi & welcome !
As Germanunkol already said, try providing a *.love file for us - we can open it without problems
The Game
The first menu is good. It's minimalistic and clean, the graphics are good, too ( just the background isn't that great ). One thing I'm missing is an exit button or a functional escape key which closes the game.
The game itself is easy, the graphics seems to be improvised / placeholder graphics, so its fine. The movement is fast and works good, I find it kinda annoying how these hostile objects pop up on the screen, you maybe could make them spawn outside of the visible area.
The game over screen is okay, the score value looks bad scaled, I would solve this with a own font I load in the right size. If you'd drawn the guy in the lower left corner, why not drawing more stuff like that for the rest of the game, he looks pretty cool
Overall I thing it's pretty good for a first project. There's still a lot free space for adding new stuff to make the game more fun to play.
I would suggest make the entities in your game smaller so the hostile things need more time to pass the screen and the player has more space to move. This would result in a easier gameplay at the beginning, but then I would add some new stuff to let the player sweat
The code
As Germanunkol said it's easy to look at the code inside a combined .exe file, I hope this is no problem for you.
I like how you struct your code and putted everything inside it's own .lua file. The code is easy to read and therefor easy to maintain. Good job.
I've seen that you require "game" and "player" everytime ( globally ), why not just require them inside the main, they then should be accessable inside the other files as well.
Also I wanna note that this file size is way to massive for this kind of game, you should try convert the .mp3 to .ogg. Also instead of paint a image with 800x600 px (where each file then is about ~350 - 400kb big) you could try to just save images with the single elements as small as possible and then put them togehter via the source code. It's more flexible and the size of the files is greatly reduced.
So, thats it. Keep working on that