Games that haven't changed in ten years

Metal Slug (Neo Geo, GBA, PSone, PS2, PSP, Saturn)
The recent Metal Slug Anthology was a great collection, but if you play the most recent addition (Metal Slug 6 ) followed by the original, all you'll notice is a slight difference in speed in favor of the new game, and a few more frames of animation. The rest of the game plays pretty much identically.

Of course, in Metal Slug 's case, that's not a bad thing - making it through the levels without dying, whilst freeing all of the prisoners is a majorly tough yet rewarding task... but how many of you actually bought all of the games in their original incarnations? When you've played one, you've arguably played them all.

Above: Play them all in Metal Slug Anthology. Luckily it's a budget title...