Master System card slot
Sure, it's an obsolete console, but did anyone ever use the card slot on their Sega Master System? Outdated even when they were current, these were basic, tiny games that no-one cared about. Good to collect, though, if only to give your little DS game cards something to look up to.
DS voice chat
There are about *counts on fingers* … two games that use in-game voice chat on DS. Come on, Nintendo – if you can do it, do do it!
PSP screen for PS3 games
That Formula One demo with the PSP acting as a mirror was way cool. Didn't happen though, did it? Bah.
Above: This never happened. Not just in the F1 game, but ever in any PS3 game to date
The CD player
In the fifteen years since the first CD-based consoles came out, we have played a CD on a console once as a genuine decision (the 360 was on and idle, so why not). Sega Saturn had a cool pitch-shift feature for transposing songs (great for guitarists/crap singers), but that's a rare and useful tool. And come on - who doesn't have a stereo these days with better speakers than the TV? Exactly.
PSone games on PS2
Strange, this – we hardly ever used our PS2 to play PSone games. And yet we find ourselves doing it on PS3 and PSP rather frequently. Very, very strange.
An utterly superb idea for a peripheral. It's a memory card. It's a games console. It's an extra screen for tactical use during games. It's a data-sharing system between users.
But in practical use, it's just a memory card. Sadly, the battery life destroys the 'games machine' potential, developers mostly ignored it and we can only remember using it mid-game for changing formations on UEFA Soccer. What a waste. Oh, but the stick-man version of Virtua Tennis that appeared on the VMU screen while you played the real game was awesome.