Rendered image doesn't show what Rendered Viewport shows... (pictures below) It's kind of an interesting result.

Here is how render viewport should look on frame 1:



Here is what happens when I press F12:



It's like I have a second camera (although I don't) somewhere below. What is even weirder is that If I place the camera behind the wall...



it shows everything correctly (example cube is seen):



As you can see, my camera is following an object that is on Bezier curve WHILE being on Bezier curve (right) itself. This animation is working perfectly on rendered viewport but not if I use ctrl+F12. Just the same grey viewpoint.

What could be the issue?
You appear to have a plane in front of your objects and the camera:



Which is not visible in the file because it was hidden:



You could either delete the Plane object or hide it from the camera render (Check the camera icon).