Well I did finish one tonight, Jade Empire.
Three to go and it is the 26th now. lol
There's no shortage of short (and free) games to play. Recently I've finished:
Jelly no Puzzle (I guess the length really depends on your puzzle solving ability)
Cat Planet (Cat planet! It's 15-20 mins long. Cat planet!)
Perspective (actually a genuinely good puzzle game from DigiPen students)