I remember Amos. I chose Blitz instead, but Amos was good, too. Another Click and Create or other gamemaker tool would be good. I've created small games with www.gamemaker.nl's tool, and it's easy. IMHO the computer industry should have more advanced (or basic depending on viewpoint) tools for creating applications that need less programming, but that's another post topic.
Blitz was better at the time because its functions were thinly transparent abstractions of the Amiga libraries or custom chip functions. Amos will be a better target for future programs, however, since it's high-level functionality is more abstract than Blitz's.
I looked into a game maker for Amiga called Backbone that was written in Amos but their Yahoo group's been taken over by hackers and the moderator's email is bouncing. I'm hoping that the new object-oriented plug-in feature will make the programming a lot easier.
Likewise the syntax tree may be made flexible enough that other front-ends can be written for Mattathias including icon-based syntax if you like. But first things first, we need to get the plug-in system working first, then the Amos compatibility extension(s).