Is my BootCamp-ed Windows seeing less VRAM than my Macbook (Pro, 13", mid-2014) actually has? If so, how can I make it see that it has more? (TL;DR below)

So I've recently installed Windows on my mid-2014 Macbook Pro Retina 13" to play some games. I never expected super incredible performance in 3D games, but nevertheless I have been severely disappointed with it and I wonder if there's something wrong with my hardware or drivers.

Games such as The Witness (a puzzle game in 3D with stylized graphics and no action) and Spec Ops: The Line (a shooter that wasn't super graphically flashy even when it was released, in 2012), barely even ran, and had to be configured with the absolute minimum graphics settings for them to reach 20—30fps. Same thing with Rocket League, a super accessible sports-racing hybrid that any half-decent budget machine can run decently. The worst, though, was Lovers in a Dangerous Spacetime, a flat 2D game — it ran more smoothly on my friend's much, much older and weaker non-Apple laptop.


  
  I had to lower my resolution for this.


Knowing next to nothing about hardware, I did a bit of research and found out that my machine has Intel Iris Graphics and, most interestingly, that macOS dynamically allocates up to 1.5GB of system memory to the graphics card. 

However, when I was on Windows, I went into Can You Run It? and used its system diagnosis tools to test my specs against the minimum requirements for some games (nothing fancy, I didn't check against the new 2016 Doom game or even GTA V). Every result said that I didn't meet even the minimum requirements for the games (even for games that I had actually ran already) because, according to it, I only have 112.5 MB of available video RAM on Windows.

So I'm thinking that that is actually the problem. 


Is this really all the memory I can have?

TL;DR: Actual question(s)

Can Windows allocate more than 112.5 MB of RAM to graphics?

Is it capable of doing that dynamically the way macOS does? If not, is there a way to force this to a different amount of RAM, since it's apparently using the minimum possible amount? (My machine has 8GB, it would be no problem dedicating 2GB of those to graphics, maybe even more since all I do on Windows is open Steam.) 

I'm using Windows 10 with the Bootcamp-provided drivers. Didn't manually update a thing, for fear of breaking compatibility. 

Even if I'm completely off-track here and my entire line of reasoning is faulty, is there anything else I can do to eek more graphical performance from my machine under Bootcamped Windows?

Thanks so much for your time.
Windows can allocate as much video memory as the driver allows. So the problem is not really with Windows, but the driver that Apple provides for that system. Yes Apple wrote the Windows driver for bootcamp on your Mac.

I don't have specific experiences with this but I have heard of people going directly to the manufacturers web site and downloading the drivers for the specific version of Windows and the graphics card in your Mac. Often this will work for other system hardware as well.

The worst that should happen is that you'll have to boot into safe mode to remove the driver, assuming you can find it on Intel's web site and get it to install.