It’s basically an ecchi version of Geschenkt.
WARNING! Contains NSFW material!
It’s a bit of hassle to explain the rules from beginning, so you can just check it out here.
The goal of the game is to defeat the loli while collecting specific tiles in order to unlock more options such as… well, you know, typical doable stuffs in ecchi games. Keep in mind it’s still in ecchi territory so you might find what you get as softcore and limited to eye-candy only.
BUT ENOUGH TALK! PLAY THE GAME HERE!
And here is how my loli ended up look like in my last game before I deemed it as too easy.