The simplicity of the rules may turn some people off. A miniatures game is really just a wargame, and most wargamers like their rules to be fairly complex, so they can model reality a bit closer than simpler rules can. That is, closer to a simulation than to a game. This is just a game. It's a good game, but it doesn't pretend to be a simulation.
Realism is bypassed to get to playability.
This can be a plus or a minus to you, depending on your tastes. This is remedied by using other marbles, of course, but I wonder why he chose clear marbles. This may not be to your taste. There are a few holes in the rules, to be honest - not every possible situation is covered. I don't mind such things - I can fill in rules with my own easily enough, and even enjoy doing so, but you might not be of the same mindset as I am.