Update

After snooping around there’s an entire section on Japanese Wikipedia’s page for unreleased titles on their page for Super Famicom Games, and it does include Amusing Dreams. The Wikipedia page cites page 15 of a book that’s an entire list of unreleased Super Famicom. I’ve checked and it’s available on Amazon as both a physical copy and Kindle Edition for about ¥19,000. Unfortunately, I can’t tell if it provides any more information that we don’t already know.

For what it’s worth this is it: https://www.amazon.co.jp/スーパーファミコン-ゲームボーイ発売中止ゲーム図鑑-ゲームラボ選書-鯨武-長之介/dp/4866733047