For anyone else that may be experiencing similar issues — please try running Please Be Happy using an alternate graphics API renderer.
To do so, please download Please Be Happy 1.1.1 - Launch using alternate graphics API renderer [129C8E3F].zip, and extract the included *.sh and *.cmd files into the same folder as your copy of Please Be Happy.
(※ In other words, the files should be in the same directory as PleaseBeHappy.exe, PleaseBeHappy.app, or PleaseBeHappy.x86_64.)
For an ELI5 non-technical explanation, each “graphics API renderer backend” is basically just a different way for the game to be able to use your GPU.
Okay, but which option do I pick if I’m having issues?
Most of the reports that we have received of this issue come from Intel GPU users — the OpenGL renderer should fix the strange memory allocation issues that seem to occur with Vulkan on Intel GPUs.
However, if it does not fix it for you, please feel free to experiment with whichever graphics API works best for you. (※ One person in particular reported that they had the best results with Direct3D 11.)
※ NOTE: All future versions of Please Be Happy (even the Steam version, which has a built-in / easier way to switch graphics API renderers) will include the launcher in the filesystem by default — 1.1.1 will be the only version that ships it in a separate file like this.