Thank you for the info, the game is only set to run at 30 fps - which I went with because it was a pretty common fps for retro games -personally that feels natural to me, but I play a lot of 30 fps old retro games. I had considered raising it to 60 fps and maybe on a better machine /setup like yours that 30 fps is more noticeable -will definitely add 60 fps at the very least as an optional setting when we get the menus going.
As far as the juddering/ fps dips I'm not sure about that one yet -I'm on an laptop thats like 7 years old with medium-ish specs i5 2.5 ghz 8gb ddr3 no gfx just crappy integrated intel gfx lol and I don't get a single fps dip from 30 so that one has me baffled -but I will certainly continue to look for ways to optimize and make sure there are no memory leaks. Anyway, thanks again for letting me know about this, will definitely try to fix and improve it!
Some time in the future if you wouldn't mind: would it be okay if I had you try a couple versions of the game to play test along with a few questions to help me isolate what could be causing that?