Have you tried using our app? https://itch.io/app it might give your more information.
For the browser, if you're comfortable with your browser's console, you can check the network tab after starting the download. A new entry will appear when the download should start, and if it's failing then you might be able to see an error message.
Alright I got the following error message (IP addresses redacted):
htfs.Open (initial request): htfs connect: Get <a href="<a href="https://w3g3a5v6.ssl.hwcdn.net/upload2/game/422618/1432217?GoogleAccessId=uploader@moonscript2.iam.gserviceaccount.com&Expires=1558014752&Signature=k4F3D8f3YiNvRCUUoAkQY8s3%2BRp5moTDFeo2WADQ1mCn7vlFDqqVM%2FhJJniw%2FUYY2IANPv6YrGUzvrQLQI8UsJjIIdiDGRHClr7sv%2BmH9XDKT8EaNRPN%2BFn%2BHOAuOSoEw2t62YSSe%2Bdcs88FnH4SsYCPH8NwN17RQJhCLuT%2BFU8cMv2cMvGvHWKBvMWf48qGM47qItzwEAqciNTKNggVcrCv7riVdfMeBJwYlct7nHrkQ3Wd%2BEGiWwdA03Xmv9z5DXDkMXjn1OkU2cuCye07evTGHzQEFuTeU4kGYTUbAhPz8%2BiRSix9ibcx%2F9G0M6ksh1T988XPceeFgE91dF9pjg==&hwexp=1558015047&hwsig=74cabc246cb279f39dbe5c388c73f42d:">https://w3g3a5v6.ssl.hwcdn.net/upload2/game/422618/1432217?GoogleAccessId=uploader@moonscript2.iam.gserviceaccount.com&Expires=1558014752&Signature=k4F3D8f3YiNvRCUUoAkQY8s3%2BRp5moTDFeo2WADQ1mCn7vlFDqqVM%2FhJJniw%2FUYY2IANPv6YrGUzvrQLQI8UsJjIIdiDGRHClr7sv%2BmH9XDKT8EaNRPN%2BFn%2BHOAuOSoEw2t62YSSe%2Bdcs88FnH4SsYCPH8NwN17RQJhCLuT%2BFU8cMv2cMvGvHWKBvMWf48qGM47qItzwEAqciNTKNggVcrCv7riVdfMeBJwYlct7nHrkQ3Wd%2BEGiWwdA03Xmv9z5DXDkMXjn1OkU2cuCye07evTGHzQEFuTeU4kGYTUbAhPz8%2BiRSix9ibcx%2F9G0M6ksh1T988XPceeFgE91dF9pjg==&hwexp=1558015047&hwsig=74cabc246cb279f39dbe5c388c73f42d:</a>"><a href="https://w3g3a5v6.ssl.hwcdn.net/upload2/game/422618/1432217?GoogleAccessId=uploader@moonscript2.iam.gserviceaccount.com&Expires=1558014752&Signature=k4F3D8f3YiNvRCUUoAkQY8s3%2BRp5moTDFeo2WADQ1mCn7vlFDqqVM%2FhJJniw%2FUYY2IANPv6YrGUzvrQLQI8UsJjIIdiDGRHClr7sv%2BmH9XDKT8EaNRPN%2BFn%2BHOAuOSoEw2t62YSSe%2Bdcs88FnH4SsYCPH8NwN17RQJhCLuT%2BFU8cMv2cMvGvHWKBvMWf48qGM47qItzwEAqciNTKNggVcrCv7riVdfMeBJwYlct7nHrkQ3Wd%2BEGiWwdA03Xmv9z5DXDkMXjn1OkU2cuCye07evTGHzQEFuTeU4kGYTUbAhPz8%2BiRSix9ibcx%2F9G0M6ksh1T988XPceeFgE91dF9pjg==&hwexp=1558015047&hwsig=74cabc246cb279f39dbe5c388c73f42d:</a>">https://w3g3a5v6.ssl.hwcdn.net/upload2/game/422618/1432217?GoogleAccessId=uploader@moonscript2.iam.gserviceaccount.com&Expires=1558014752&Signature=k4F3D8f3YiNvRCUUoAkQY8s3%2BRp5moTDFeo2WADQ1mCn7vlFDqqVM%2FhJJniw%2FUYY2IANPv6YrGUzvrQLQI8UsJjIIdiDGRHClr7sv%2BmH9XDKT8EaNRPN%2BFn%2BHOAuOSoEw2t62YSSe%2Bdcs88FnH4SsYCPH8NwN17RQJhCLuT%2BFU8cMv2cMvGvHWKBvMWf48qGM47qItzwEAqciNTKNggVcrCv7riVdfMeBJwYlct7nHrkQ3Wd%2BEGiWwdA03Xmv9z5DXDkMXjn1OkU2cuCye07evTGHzQEFuTeU4kGYTUbAhPz8%2BiRSix9ibcx%2F9G0M6ksh1T988XPceeFgE91dF9pjg==&hwexp=1558015047&hwsig=74cabc246cb279f39dbe5c388c73f42d:</a></a> read tcp IP:PORT->IP:PORT: wsarecv: An existing connection was forcibly closed by the remote host.
So I tried https://www.stackpath.com/highwinds/ using http://cloudharmony.com/speedtest-for-highwinds and there weren't any issues. Although going directly to the hwcdn page from the download does result in an "ERR_CONNECTION_RESET" error.
