A cool clock!
This is a Sonic 2 themed wall clock. It was made in 1992 (so, right around the time of Sonic 2 release) It is flat, and sits a bit away from the wall. The edge is checkered, and features Sonic & Tails art running along it as if the face were a loop from the game. The Sonic 2 logo is at the top, with the Japanese art of Sonic doing a peace sign/2 fingers in a ring of stars.
Look at the pendulum, it's Eggman in his egg-o-matic! He's hanging by a chain of 'rings', and has the spike-ball-dropper attachment on his vehicle. He really swings back and forth while the clock is ticking! You can literally "watch the clock" at Sonic 2 Wall Clock Footage, with that link to the video.

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