Crashed Game When Opened

Expectation:
I expected to open and play Minecraft normally.
What Actually Happened:
The Minecraft window appeared but it instantly closed and the launcher re-opened to display what happened and where the Crash Report could be found.
Steps to Reproduce:
I'm not actually sure if you can reproduce this, but I'll type the instructions anyway:
1. Open the Minecraft Launcher.
2. Press the play button to launch Minecraft.
3. Watch as the windows appears but instantly disappears to display log information in the launcher.
Extra Information:
I tried reinstalling Minecraft but that didn't help, and as you know, the crash reports file is created only when the game crashes, but there for some reason wasn't a crash reports file present in my .minecraft file.
Also, I recently tweaked with the settings file, and it seems to be since then, the game started doing this, so I'll try and change them back to their defaults, but as I said earlier, I reinstalled Minecraft, so wouldn't the options file be restored anyway? Thanks-
Anton Smith - AKA TitaniumGamingMC