To leave a bit more of a detailed review than others: its a good pack but you may not need it.
As a collection of a variety of things, its a decent deal - for 10 bucks you get what is stated on the page, a bunch of variety shaders, icons and effects to use in the project. They might not fit your project exactly but its easy enough to adjust - its godot after all.
However, thing is that a part of these effects, especially particles, are easy enough to make yourself if you are capable enough to ajdust them to your project later. If you arent, you sure can buy it and use them as-is, no question there. Similarly, a chunk of shaders (or really similar ones) in the project is available for free on godotshaders website, like the toon stylisation or water shaders. The plasma shader is effectively a copy of the plasma shader from godotshaders which itself is a copy of the shader from shadertoy which has a license prohibiting it from being used for commercial purposes and has to be shared under the same license. Edit: The plasma shader was removed, kudos to Bukkbeek for honoring the license of the original.
But to also be fair, a large portion of things here is very well done original work, as far as I can tell, and can come in useful for anyone who wants to spend a bit of money instead of devtime to have all these FX. Looking forward to next versions and improvements - like an update to the latest engine version (though it ultimately doesnt matter), fixes to the effects (aforementioned plasma being one-way while everything else like the electric waves near it arent), flag sway being a bit randomised instead of being exactly the same loop, etc.