Supreme Leader: Cold War is a very intense game. It's the only game in recent memory in which I had to read the PDF instruction manual in order to know what to do. This is in no way a bad thing; it simply reminded me that we can take certain things for granted in this day and age. It plays out as a way more in-depth version of Civilization with more historical context.
As I mentioned, the first thing you're going to need to do is read over the instruction manual that comes in the game's install folder. There's also a "Quick Guide for Beginners" PDF that does a great job of quickly going over the most important features of the game that you'll need to pay attention to. Reading the 74 page manual is a bit overwhelming, so it's best to slowly introduce new game elements as you see fit.
The Campaign Mode lets you pick between the United States and the USSR during the Cold War. From that point you're on your own to manage your entire country. This includes things like tax rates, defense spending, military consumption, diplomacy, the Space Race, and even the DEFCON level. Luckily many of these things are initially taken care of automatically by your cabinet members. As you slowly grasp more elements you can start to fine tune them yourself. If you're up to it, you can manage every aspect to your country to the smallest detail.
Sandbox mode allows you to pick from just about any country and play however you'd like during the Cold War. This mode is great to pick a smaller country and not have the overwhelming sense of responsibility that comes with managing huge countries like the US or USSR. You can even pick some involved countries like Cuba and possibly alter the result of the Cold War is a very big way. The possibilities in this mode are almost endless and it can be quite entertaining.
There's also a Scenario mode that gives you a certain objective to complete as a specific country, like helping out South Korea as the United States. It's nice to have a clear and concise objective while playing as it makes all of your actions seem more important in the short-run. There are a few included within the game and it also allows for custom scenarios.

Accessibility Issues/Concerns
The game includes a pause button that can be pressed at any time using the mouse. It also allows you to alter the game speed from very slow to very fast. The entire game is controlled with the mouse, though there are keyboard shortcuts as well. While there is no remapping for the keyboard shortcuts, there are a ton of other options that can be turned on and off at your whim, such as the ability to have the game pause itself whenever an important event occurs. There is no mouse sensitivity option either.
The game plays an alert sound whenever a notification pops up on the right-hand side of the screen. The notification also comes with a visual cue though, as the corresponding box will light up and adds a number to the number of notifications. Besides that, there are no crucial audio cues.
Color occasionally comes into play when seeing how friendly other nations and cities are with you. The game uses different shades of red and blue to distinguish how unfriendly/friendly someone is which may be hard to see for colorblind gamers. The number for how many notifications you have is also quite tiny, so low-vision gamers may have a difficult time know just how many notifications are there with a quick glance.

At a Glance
Mobility: The game can be controlled entirely with the mouse, though there is no mouse sensitivity option. Tons of extra options that can make the game even more playable are also included. There is also a pause button and various game speeds that you can change at any time.
Score: 9/10

Hearing: An audio cue is played when you gain a notification, though it is accompanied with a slight visual cue as well.
Score: 9/10

Vision: Some color shades are used to signify friendship status between nations. The notification numbers can be hard to read as they are quite small. Menus are easy to read.
Score: 6/10

Overall: Allow me to state this one more time for your convenience: be sure to read the game's manual. There is a lot going on in Supreme Leader: Cold War and you won't exactly understand all of it by just jumping in head first. The game is mostly accessible as well, but make sure that you're ready to get involved with this behemoth of a game before you begin.