I am experiencing the same issue.
I am making a STG game, when using input(pressing arrow key and Z), there are tiny lags every several seconds. And sometimes it would be in slow motion(cannot reproduce), when you keep pressing keys, it get slower, otherwise it will return to normal.
I believe it is related to Input handling, or it is caused by GC(unlikely) because that inputs will initialize lots of Vector and Bullet.
My environment is Windows 8, Ruby 2.3.0 x86, and I've tested on Ubuntu the demo is working well.
my repo https://github.com/CicholGricenchos/toho-like-rb
, use arrow keys to move and Z to fire.
I could upload a video clip later representing the tiny lags if needed.
Here is the video clip and you can see the character is shaking when moving left/right. This issue doesn't show on Ubuntu.
, doesn't help this case.
And I tried Ruby 2.1.8/1.9.3 with Gosu 0.9.0 ,it is almost the same.