Probably the best game on this list (apart from Wario Land) it's bittersweet that Bound High was never officially released. I doubt if it could have saved the Virtual Boy, quite like re-arranging deck chairs on the Titanic, but it would have been a nice sending off gift for die hard fans of the system.
Bound High is the sort of game you might expect to see on a smartphone these days. It's dead simple but addictive, and each new stage introduces additional gameplay modifiers that keep things fresh throughout. You're basically a transparent sphere that bounces.
The entire playfield scales larger and smaller according to your height. This, coupled with the Virtual Boy's proper depth perception, creates an extremely convincing sensation of falling and rising. The goal is to eliminate all the enemies in each stage, but there's more than one way to do that.
You can of course just fall on their heads. Some enemies die instantly when struck this way. Some take 2 or 3 hits. But some can't be killed this way. Instead, every time you hit a square section of the playfield it vanishes. You can use this to eliminate the floor out from under enemies, causing them to fall to their doom.
Keep in mind you don't get the 3D effect from this video, which is a large part of what makes gameplay exhilarating. Stylistically it reminds me a great deal of the various Bomberman games. I found it charming, fun and it's clear a lot of love went into its development.
Shame, then, that it never got a release. But I'm glad it leaked many years later so people could enjoy it anyway. I give Bound High an 8/10.
Stay Cozy!