If you're feeling stuck for games to play today, then here's a suggestion: try Q.U.B.E, the puzzler from 2012 about manipulating coloured blocks with sci-fi gloves. It's free for the next 24 hours or so, it'll only take you three hours to complete, and it's a smart game with lots of good ideas. Click here to grab it.
Don't expect flashy visuals—its environments are mainly sparse, sterile white rooms punctuated by the coloured blocks, and it definitely lacks a bit of personality. Still, I think it's worth playing, and so did our review at the time, which argued that some of its puzzles were "almost as impressive" as Portal's. High praise indeed.
The Steam version is a Director's Cut that adds in story elements to the original, which do at least provide some context for what's going on.
The reason it's free is because its sequel is coming out next week (March 13). Q.U.B.E 2 is looking like a far more polished package than the first game: Austin enjoyed his time with it back in January.
If you try Q.U.B.E and like it enough to buy it, then it's 75% off, making it just $2.50/£1.74. That deal lasts until Monday, while the game is free until midday PST tomorrow (8pm UK time).