Recently I played ddnet on my iPhone using steamlink (the game was launched on my PC and was streamed on my phone screen using this steamlink thing)
Also I used PS4 controller to play because it wasn't possible to play without it at all(only chat)
It's funny that u can play ddnet like this but unfortunately I can't say it's playable, especially about aiming somewhere, it's close to impossible for me to aim correctly. But if the map needs only a/d, jump and maybe hammer then yea EZ map xd