When sliding through a blocky two color world, keep one thing in mind: Space is Key. Actually, if you're playing this painfully challenging arcade game on your iOS device, that title isn't as true. With the browser versions of Space is Key and Space is Key 2, all you do is tap the [spacebar] to jump, hence the name. On a touch screen there is no spacebar, so instead, your finger is key. That's a bit of an awkward title for a game, though, so instead of brain thinking, we'll game playing!

Games don't get much simpler than this; just hit a key to jump over an obstacle. Easy, right? Well, Chris Jeffrey's reflex-demanding one-button arcade game might just prove you wrong across twenty sadistic levels. With its snappy presentation and straight-forward gameplay, Space is Key 2 is hardly innovative, but it is a well polished little torture device for your reflexes. More than anything, it's a great illustration of how hard you can force players to push themselves at a simple concept just by implying it should be easy.