Cool you noticed. It's actually ExpendaBros. The Explendables skinning of Bro Force. I'm using 3 buttons attack, grenade, special attack. I had a lot of fun playing with the 3 buttons I was using. Up works as jump.
I haz it. I got the free game like you, but I also bought the actual broforce game too. Whoever their pixel artist is for the portraits......he does amazeballs work.
*LOVE* your button layout BTW 
I've wanted Bro Force for awhile but decided on Mercenary Kings first. Expenda Bros is awesome! I'm glad I found out it was free; didn't they used to charge? Can you tell me if it uses the same control scheme? I hope you say yes. Also, what is the max player? Is 2 or more with gamepads?
Thanks for the kind words on the layout. You might be surpised to know that player 2 is the opposite, solid rings and clear plungers. It looks nice, but I have it wired wonky though. I'll fix it when I have a game I need it fixing for. One day I'll
Neph it up and light the buttons based on the game.
It's supposed to be
X X X
1 2 3 4
And I'm supposed to change it with ini's but I never got around to doing that. I have this peculiar fantasy that I'll get MKKE and Injustice playble, but haven't.
Config your mame inis before its playable friends and neighbors!