Update:
After a long time, Ludo has once again delivered!
The highly-anticipated secret project is finally here!
Except it wasn't a secret anymore. Especially after some people posted screenshots about the supposed project.
As you people know, Little Princess is an insanely illogical ADV game created by Alicesoft, which in that time was going by the name Champion Soft. It tells the story of Ogawa Kentarou's adventure to save Kurusu Miki after she had been kidnapped by Count Dracula (he was retconned into current canon as Demon King Gi). The game uses a command type gameplay in which you type a 'verb' 'noun' to execute different commands in the game. The thrill is that you have no hint or idea what to do. Even TADA himself had commented that he really didn't know what the heck was happening. That was after replaying it though. You continue typing these commands until you reach your destination, Count Dracula's castle. That's where you'll be saving Miki.
Of course, the game is insanely illogical, so don't be surprised if you suddenly hit a dead end. It's natural. I recommend playing it without a playthrough, since you'll be having fun actually trying out different commands to satisfy whatever conditions you need to satisfy!
The official translation post is here.
Also, fun fact: