Got all the coins after a while! It'd been some time since a game put me to the test while keeping me motivated to achieve it.
Nothing beats that "you are very skilled" screen after getting all the coins at the end. The satisfaction of achieving everything in a game, in a way that it isn't a timesink but a show of skill... something sort of forgotten in games of late, yet this one has it down to an art.
This game may not be very original, but it encapsulates rather neatly what games should be about. In a world of Gone Home, Dear Esther and Beyond Two Souls... this feels reassuring. Thanks.