I didn't realize a controller was non-optional. Seems to work with an Xbox Controller connected over Bluetooth, Chrome 76 on Windows 10 1809. It doesn't run at all in Waterfox 56.2.14.
The art style and janky gameplay really remind me of mid-2000s Flash games. I could definitely see this on Newgrounds some time in the previous decades.
Although, to be honest, it would have been one I checked out, thought was cool for a few minutes and moved on from. The gameplay wasn't really satisfying and I couldn't get past the giant barrel boss. To be clear, a lot of this is down to personal preference; I'm not really into games like Double Dragon to begin with.
And I suspect if you're one isn't familiar with the source material a lot of it is going to be lost on them. I think it really falls into "it's a decent entry but not really my thing" for me.
EDIT: To clarify the last line because it comes across as a rambly mess: I think you have to be familiar with Double Dragon to really get this one, and I'm not really familiar with it so it just didn't click for me.