You are searching for a game where you only can remember a part of the gameplay or some screens? Then you can use the Amstrad CPC Screenshot Catalog, which was assembled by Lex Sparrow and ZX4Ever, to find the game. It currently contains more than 3500 screenshots (only in-game screens – v1.0 contained loading screens, too).

You can download the PDF file from PressPlayThenAnyKey or the CPCWiki share hosting.