ffmpeg - Unable to find a suitable output format This is a part of my command:

-r 60 -preset medium -codec:v libx265 -ar 48000 -acodec aac -shortest -strict experimental -sn -vsync 1 -pix_fmt yuv420p -b:v 30000000 -movflags +faststart  -x265-params high-tier=0:pmode=1:wpp=1:tune=fastdecode :bitrate=30000:fps=60:keyint=360:min-keyint=180:vbv-bufsize=30000:vbv-maxrate=30000:scenecut=0  -metadata title


and when i run it i get the following error:


  Unable to find a suitable output format for
  ':bitrate=30000:fps=60:keyint=360:min-keyint=180:vbv-bufsize=30000:vbv-maxrate=30000:scenecut=0'
  :bitrate=30000:fps=60:keyint=360:min-keyint=180:vbv-bufsize=30000:vbv-maxrate=30000:scenecut=0:
  Invalid argument


I think there might be a missing space or something like that somewhere but i'm not too sure what's wrong with this syntax?

Thanks!
...tune=fastdecode :bitrate=30000... 
                 ^^^


There's a space that should not be there.