Proving prior art is often should be as simple as presenting an obvious proof and have the patent invalidated in the same day as long as the records are not debatable.
What you're talking about almost exists, it's called an inter partes review[0]. The problem is, the records are almost always debatable. The legal system affords scoundrels plenty of opportunities to file paperwork.
As it stands, IPR works enough that patent trolls are angry that it's too easy to get junk patents thrown out. But it still requires you to know in advance what to fight, to spend money on lawyers fighting it, and to delay actually using the invention you think isn't patented until the patent is actually thrown out. Some developer who independently invents loading screen mini-games probably isn't going to even know about the loading screen games patent until either legal tells them to remove the mini-game or they launch and get sued by Namco.
An example of this: do you remember VRML chatrooms? Worlds, Inc was one of them, and they got US8082501B2[1], a patent on having a character in a multiplayer virtual world. They sued Activision[2] over the span of nine years, while also hitting up other game developers for money, including Microsoft[3]. Microsoft actually tried filing an IPR case[4], but the courts acted first to invalidate the patent before the IPR could go through[5].
Don't forget the patents on CONTROLLERS VIBRATING for fucks sake. The reason the original PS3 controller didn't have vibration was because sony wanted to avoid paying the protection racket one time.
As if making something buzz is fucking "non-obvious"
