I just added a little TE4 button on the top right of the main menu to let TE2013 players aware the sequel will come soon... :-)
You'll find it here : https://store.steampowered.com/app/760640/Tennis_Elbow_4/
It's coming in Early Access on June 4th.
Note : the button doesn't weigh 25MB ; it's just the Steam delta-update that kinda failed... ːsteammockingː