Can't think how to create a mini game using widgets.

So I’m looking to create a cleaning mini game where a player has to scrape off dust from a dust filter. I can’t for the life of me figure out how to start this or how I would get something like this working.

The way I’ve been told it should work is the player holds down left click and moves the mouse over the dust and it should ‘clean’ filter. If anyone knows how to create something like this or can help me get started, it would be much appreciated.

The first step would be to get the hang of render targets. You can then display this texture in a widget.