PtoPOnline | Unreleased Tetris DS by THQ/TOSE on DS Development Kit @PtoPOnline | Uploaded February 2020 | Updated October 2024, 2 hours ago.
I noticed a few years back that the Tetris DS prototype, released by xkeeper & The Cutting Room Floor, outputted some nice debug information if played on the IS-Nitro-Emulator official DS development kit. This video is running on real hardware with the debug information on the lower left.

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The Cutting Room Floor: tcrf.net