cmd.exe doesn't properly render the 🦕 from welcome.js.
C:\>deno https://deno.land/welcome.js
Welcome to Deno 🦕
This is potentially confusing to newcomers.
cmd.exe doesn't support unicode... In theory we should have some information in the Deno namespace the provides information about the support of the console it is running under and be able to then allow code to feature switch.
Not sure about cmd.exe but I believe https://github.com/denoland/deno/pull/1485 will fix powershell.
The windows console doesn't support emoji at the moment, although supposedly msft people are working on that.
(Note that whether you're using cmd.exe or powershell is irrelevant, much like you wouldn't say that bash/zsh does or doesn't support emoji. Displaying characters is a feature of the terminal application, not the shell.)
The new (beta) Windows Terminal correctly displays emojis and resolves this issue (screenshot attached).
Project: https://github.com/microsoft/terminal
Store link: https://www.microsoft.com/en-us/p/windows-terminal-preview

Most helpful comment
The new (beta) Windows Terminal correctly displays emojis and resolves this issue (screenshot attached).
Project: https://github.com/microsoft/terminal
Store link: https://www.microsoft.com/en-us/p/windows-terminal-preview