For existing projects, since the API interface is the same, you can update to version 1.80.5 simply by replacing the old 1.61a dynamic library with the 1.80.5 one. Existing particle effects should continue to work without any changes.
Note that GPU Particles is not supported for OpenGL backend, see the answer from one of effekseer’s developers:
Well it’s kinda embarrassing, but I forgot to enable necessary optimizations (-O3 in this case) and forgot to link the binary against libGL on Linux, resulting in errors so a new update has been pushed to the release page