"Oh no, Grid Garden doesn't work on this browser. It requires a browser that supports CSS grid, such as the latest version of Firefox, Chrome, or Safari. Use one of those to get gardening!" I am running Chrome 56 on MacOS
It said I wasn't on Chrome... it should have said, "You're on a version of Chrome that doesn't support this..."
Telling me I wasn't on Chrome was a bug... or at best really poor UX.