This game is FAST!  Feels super responsive and snappy on real hardware too.  When a Genesis / MD game is well programmed, the hardware really shines, and it's clear to me that Gun Slugs has been carefully coded.  In terms of gameplay, I find this kind of run and gun game quite addictive.. in the best possible way.  Simple controls, rewarding objectives, and cool weapon upgrades keep me coming back for more.  Gun Slugs will blast your processor like it's 1989!