I tend to classify effects as either a) In my strolling (drinks reception set) being a limited number of items that I can perform out of my pockets; b) My table set where I am working tables again with a smallish collection of tricks, some of which I can walk around with and somewhere in the background I have stashed my 'tables' case ready to pull things out of; and c) After dinner effects where things are a bit more relaxed, the tables have been cleared and there's a lot more space on the tables to spread cards out.
Galaxian definitely fits into the after dinner category and is at the time of writing my favourite on this category. In this category I would also place Little Plunger, Little Door maybe and Rule of Three.
You present a spectator with a task to separate the reds from the blacks, demonstrating as you do so with a heart or a diamond on one pile and a spade or a club on the other. You then ask them to do this blindfolded, or rather by instinct alone whilst looking up to the ceiling. I've never yet had anyone refuse to do this probably because by the time we've got to the after dinner stage everyone realises that this is great fun and no-body is going to be humiliated by anything I do.
Naturally most people will struggle to separate reds from blacks by instinct and whilst going through the two piles afterwards you make one easy surreptitious 'move' and then turn the pack over revealing that half the deck had black backs and the other half had red backs. Your volunteer spectator is immediately vindicated with their unexpected female instincts and the reactions from the other spectators are just as gratifying.
The reset is straightforward. There are no reasons why this couldn't be immediately repeated (although I have yet to do that), there are no angle issues whatsoever and the deck can be examined although I usually like to use some of the deck straightaway for another effect so the issue of examination for me doesn't occur but I'm very confident that unless you know what your are looking for there is practically zero chance of anyone finding it.
A real winner and crowd pleaser that is simple to perform. I love it.