can someone confirm this runs on their system?

[madscijr]

The top right player didn't move until I tried to go up the first time and seemed it worked fine after that. Didn't notice an issue in the other player controls.

Thanks for your feedback!

If they're flip screen (ie non-scrolling) mode and there's a wall just off-screen blocking the way, it can seem like the controls don't work. I plan on adding sounds for when they bump into a wall. 

Another thing to look out for is checking whether num-lock is on/off, as the game uses the numeric keypad's cursor keys for one of the players.