As well as faster DAS and the like, these in-game points can also buy you, from what I can gather, new block skins, new playing field skins, new backgrounds and new voices to say "Teterisu!" when you clear Tetrises. Except you don't get to pick them. You pay 100 TP and you get a thing given to you at random. Skills are bought at 200TP for the first level, then 500, 1000 and we don't know past there. Points are quite quick to obtain though. I was playing multiplayer and getting over 30 points per game, though I was winning and against 5 or 6 people. Still, it means I don't have to touch the single-player modes to upgrade DAS and the like.