add screenshot

README.md

@@ -3,9 +3,9 @@
 A Smash TV/Robotron-like game to help me learn a whole bunch of things
 about game programming, DOS & PC programming, x86 assembler & C, and VGA graphics!
 
-<center>
-    <iframe title="DOS Arena Game -- Version 1" width="560" height="315" src="https://makertube.net/videos/embed/027d4ca0-f9ed-4f0d-b47e-15b92a197b87" frameborder="0" allowfullscreen="" sandbox="allow-same-origin allow-scripts allow-popups"></iframe>
-</center>
+![screenshot](screenshot.png)
+
+[Video of the game in action here!](https://makertube.net/w/1iQ7YYFkQjFmjuMy72Msqp)
 
 ## Play!