This is a quick and dirty method, suitable only for those who don't use Mega Hack or Geode (that requires it's own steps to get working on Windows 7)

https://github.com/i486/VxKex

This method is suitable for people who intend to use mods like Mega Hack or Geode.

Step 1: Acquiring XInput1_4.dll

The first issue you'll run into is the lack of a XInput1_4.dll file. Now, the fix to that is really simple, all you need to do is go to C:\Windows\system32, take the XInput1_3.dll file, and copy it to be called XInput1_4.dll. Put it in System32 if you plan to use Mega Hack or Geode, or put it in the Geometry Dash folder if you just plan to run Geometry Dash by itself.


Step 2: Patching out the call to GetSystemTimePreciseAsFileTime

Now, that you have gotten XInput1_4.dll, you can't run the game just yet, you'll encounter an error message about the missing entry point GetSystemTimePreciseAsFileTime in KERNEL32.dll. Now, using Dependency Walker, you can see that the file that calls this function is UV.DLL.


To patch it out, you can use a tool called CFF Explorer (https://ntcore.com/explorer-suite/). Download it, and open UV.DLL in it. Now navigate to Import Table, find KERNEL32.dll in there and scroll down until you find GetSystemTimePreciseAsFileTime. Change it to GetSystemTimeAsFileTime. The function you need to change is highligted in the image.


After that, save the file. (You may need to save it somewhere else then move it into the Geometry Dash folder)

Enjoy!

This part is simple. Just install Geode from their website: https://geode-sdk.org/install

After installing it though, you'll only see this error:

Follow the next steps to fix it.

Step 2: Enabling VxKex
I have taken a look at this, and Geode.dll calls CreateFile2 which doesn't exist in Windows 7. It's possible to fix it using VxKex but if you do that, you'll see that Geode doesn't even try to load. This is because of how VxKex works, and how tools like Mega Hack and Geode use XInput1_4.dll to inject themselves, however that can be worked around.

Step 3: Redirecting XInput1_4 to something else
For this step, firstly rename XInput1_4.dll to something else, that has the same amount of characters. For example ZInput1_4.dll
(Also, be sure to go to System32 and copy XInput1_3.dll to XInput1_4.dll if you haven't done so already)
Afterwards, open libcocos2d.dll in CFF Explorer, navigate to the Import Table and change XInput1_4.dll to your DLL name.

Then, save the file. (You might need to save it in another folder then copy it into the Geometry Dash folder.

Enjoy!