HP Notebook with i3-5005U CPU @ 2 GHz
Its got an integrated graphics card - Intel HD 5500
8 GB ram.
Windows 10 home.
It's not going to run a modern game, but I've played games like mass effect 3, the witcher 3 (with ultra low graphics) and dragon age inquisition, so I don't really understand why a game like this one, that doesn't look great to begin with, can't be run even on the lowest settings.
Like you already indicated, it does not necessarily have to do with how demanding the game is specs-wise, its more to do with what engine the game is running plus how its using said engine.
Unfortunately, 9 times out of 10, these performance issues (as well as other issues) are not present if you're using a discrete graphics card.
But when it comes to integrated GPU's, Intel Integrated Graphics are notorious for having issues in games.
I understand you're on a laptop and an upgrade may not be possible, but trust me, getting better hardware if you can, will make you a much happier gamer.
Your CPU is also low spec, although that shouldnt be causing any issues.
I'd bet money that this issue you described is solved with a graphics card upgrade.
And if you're wondering why I'm saying all that, here's why:
Your CPU has an integrated GPU, the one you're gaming on.
Imagine that there's a relatively heavy load on the CPU. Now imagine that there's also a heavy load on the GPU.
But both the CPU and GPU are on the same package.
This effectively means that when considering thermals, the CPU has to take into account the overall thermals, not just the CPU cores, but also the GPU part of it as well.
So, to sum up: Heavy load on both CPU and GPU means that your CPU will throttle sooner, boost less, and this means less CPU performance. This is in addition to the already poor performance of the Intel HD 5500.
If you werent gaming on a laptop, and were using the desktop equivalent with decent cooling (NOT Intel stock), I'd say that thermals wouldnt be an issue.
But chances are, you probably are losing some performance because of hitting thermal limits.