Unless game names are all very short - less than 8 characters - you will be best off with
Title of the guide - Name of the game
For one, many visitors may have multiple tabs open, and the first few words of the
<title> tag will appear on the tab in most browsers. So if the game name is longer than the few characters allowed in the tab, they will only see the game name there - not the particular guide they are looking at. They're likely to have other tabs about that game open so the game name is then less relevant when they're trying to switch between tabs and identify what each is about.
Similarly, visitors using a screen reader can more quickly tell what the specific page is about if you have the most specific information at the beginning. So instead of having to listen to
Long name of the game (dash) Guide (dash) Actual information that is specific to this page they can listen to
Information specific to this page (Game). Since the specific piece of content you're talking about is a guide, I would expect the word "guide" to be part of
Title of the guide and not a separate word in the title - thus my recommendation to shorten the title to 2 pieces of information rather than 3.
I think you will also find this structure best for SEO. Rather than front-loading the game name, you can target longer-tail keywords by having the
Title of the guide at the beginning, and of course you'll have the name of the game later in the title and woven throughout the content itself. You're not trying to compete for searches for
Game name - these pages should instead be competing for
Title of the guide for game name which is what this suggested title structure positions you best to compete for.