For me the game runs fine at first, but becomes unstable after creating several saves.
v0.04.2 stays stable for longer than v0.04.1, but eventually, after making a bunch of saves, still crashes at some point after I click the menu button or more often after clicking the save button and while saving the game.
When it crashes after clicking the save button, then it actually creates a working savegame, but fails to create a thumbnail for it. There is some screen flicking (you seem to be applying some kind of overlay there with the game showing through at the edges) happening while saving the game and it seems that most crashes happen at that flicking point.
And what's worse, after your game crashed several times, it kind of somehow jammed up the whole Windows directx system or GPU memory, so that I couldn't even run a Ren'Py game after that. Ren'Py warned me about the system being low on graphics resources.
There were no processes left from the game in the background, but there were no more resources available for the graphics. Even Windows Aero couldn't run any more. Restarting uxsms service didn't help, just couldn't create transparency or other eyecandy effects on the desktop any more.
Had to restart the PC to free up the clogged graphics system.
It seems to me that there is something wrong with the saving system, that every time you use it, it hogs up more resources, possibly GPU memory.
It's probably why it's more stable on PC's with more GPU memory. I haven't tried it yet, but I'm taking a guess that should I try to play the game without saving it or loading any saves, it may not crash at all.
My PC is quite old, too, but I've upgraded its RAM and GPU to have 8 gigs of RAM and a Radeon R 9 200 graphics with 3 GB of RAM. (I've been too lazy to build a new rig and I don't like pre-built or barebone PC-s. There is always something that I don't like about them.)
Still using Windows 7 SP1 because Windows 10 annoys the shit outta me and I like Windows 8.1 even less. Windows and graphics drivers are up to date and having no problems whatsoever with any other software, even the memory or graphics hogs.
The game plot and graphics are fine. I agree with what Ignatz said about it - the magical horse dick of the MC (or a huge dick in general) is not my cup of tea, but it creates an intrigue that many funny scenes are later built on, so I don't mind. (I almost snorted some beer out of my nose at the radioactive horse bite joke XD )
Just, please, try to take a look at the menu or the saving system. I'm quite sure that there is a bug in there that hogs up resources every time you use it.
I'll try that OpenGL version later, to see if that is any better. Just not today.