LEGO games have mostly been confined to kid's titles and platformers. We've yet to see a LEGO first-person shooter. If we ever do, I really hope it looks like this.
This is a bolt-action Lee Enfield sniper rifle, built to scale by Jack Streat, and made entirely out of LEGO. It's not built to just look like a rifle, it actually works as a rifle, with a spring-loaded clip (that shoots LEGO bricks), sliding bolt, scope, trigger and one hell of a punch.
The FPS action begins at around the 50-second mark, but if you skip straight to that you'll miss him loading the clip, which looks terribly cathartic.
Lee Enfield Bolt Action Sniper Rifle (working) [MOCPages, via Neatorama]