Tiny Glade needs a mid-range graphics card with up-to-date drivers. Here’s how you can check which graphics card you have - if you only have integrated Intel (U)HD Graphics, Tiny Glade will unfortunately be slow. Integrated AMD Radeon Graphics does a bit better, but you may need to tweak the settings.
Inside Tiny Glade, try going to Settings -> Video, and reducing “Resolution scale”. This parameter multiplies width and height of the resolution at which the game world is rendered. For example, a scale of 0.7 will result in 0.7 * 0.7 = 0.49 the number of pixels to be rendered. It won't quite double the performance due to other bottlenecks, but it should help a lot.
Disabling “V-Sync” might help a little bit too if the game is already running at a low frame rate.
Please check the minimal and recommended system requirements on our Steam page. If your computer meets the requirements, you've set your resolution and "Resolution scale" to reasonable values, and Tiny Glade still runs slowly, please let us know in Steam forums.
Please note that our in-game feedback tool (F6) allows you to send us performance info via an integrated benchmark, which is very useful in diagnosing these kinds of issues.