Using a compatible all in one cooler it was possible to overclock the Xeon X5460 to 3.75 GHz. It can now comfortably play Battlefront 2 and PUBG, and almost play Battlefield 1.
The GPD Win 2 has an m3 inside, which makes it capable of playing a wide range of AAA games on low settings/resolution like DOOM, Fornite, Rocket League, Skyrim SE, Dragon Ball FighterZ and Metal Gear Solid 5.
Devil May Cry 4 SE can be made to run on an Intel Atom with some changes on .exe to remove some post effects.
A free benchmark tool was released for Final Fantasy XV. Graphics are locked to some presets, but there are ways of tweaking the settings to traumatizingly low levels. This can be used for great performance on entry-level gaming PCs.
The R7 350 can be imported from China for $100, or about the price of a GT 1030 in Europe. While the architecture is older the clock slower it packs a whopping 4 GB of VRAM. This is useful for games like PUBG, GTA V and Wolfstein 2.
If you have access to an old 775 socket motherboard and a used GPU you can find modded Xeon CPUs on aliexpress that perform similarly to cheap gaming quad cores. Except for some of the most CPU heavy modern games, this setup can game well.
Adding 2 GB of RAM and a used Radeon HD 5850 GPU can take the TrasTop Pentium to an acceptable level of performance on modern games while still maintaining a budget of less €100.
I found someone throwing away an almost full PC for 25 euro. It has a G860 Pentium Sandy Bridge Dual Core CPU. All that was needed was a hard drive and RAM. It is a good start but could use a dedicated GPU.
With the correct adjustments, the first Crysis game can be made to run on a tiny Intel Atom PC. This makes gameplay very difficult but provides good performance.
The GTX 750 Ti performs around 10% better than the GT 1030. GTX 750 Ti availability and price is dependant on second-hand markets. The GT 1030 tends to be available for a better price in more countries. The winner depends on where you live.
A Hat in Time is playable on a dual core IntelHD with the help of some tweaks. If you reach the main configuration file you can easily change post effects, shadows, draw distance, textures resolution and other details.