[Question] Unique game mechanics -- The best and the worst

For action games, I still view Bionic Commando as having among the most competent and unique game mechanics in the genre. Yes the game is old, but introduced a very competent gameplay mechanic which directly correlated with a fun gaming experience.

The mechanics stem around the lack of jump button and the addition of a grappling hook, which you can use to quickly move about from place to place. As much of the levels are sprawling landscapes, each featuring different heights of infrastructure and terrain, it made traversing through each stage very interesting and novel, which is something that has yet to be properly expounded upon in modern games.
For an action game, the ability to jump is almost a given so it was quite strange not to find that element when Bionic Commando was first introduced. However, once the grappling hook was mastered, it was ultimately very effective and added a different layer of depth to BC's gameplay.

Another game with honorable 'grappling mention' would of course be Super Metroid though it didn't quite figure into the gameplay to the extent of BC.

I admire that the new Contra game is going to put a grappling hook at the player's disposal. I can't wait to see how it fleshes out.

Jam it back in, in the dark.