With contrast, everything should be fine, on the contrary, the terrain tiles and spaceships are very bright, while the background is very dark. The only special feature is the low contrast between the background and asteroids. Initially, asteroids were made in several color options, but now the game only has the darkest version of asteroids, which are faintly distinguishable from the background. This was a deliberate choice to make make asteroids less visible, so that their appearance often comes as a surprise to the player :-) Bright asteroids are too easy to play with :-)
However, the game uses a linear color space rather than the outdated gamma color space, but I don't think that this can cause problems with contrast on the MacBook.
I don't really understand what mean "jerky" - is it input lag, freezing, image jitter or background jitter while ship moving? There should be no problems with lags, the game runs absolutely smoothly both for WebGL and Standalone versions, but there may be problems with the background image in the Web version. You should also keep in mind that the game was developed for a resolution of at least 720p (1080p is better), so there may be noticeable artifacts in a small browser window (there are none in full-screen mode), also game uses the 2nd version of the graphic API for WebGL version. in general, the images in WebGL and Windows versions are slightly different. I think if you look at the two images below, you will immediately see the differences between the PC and WebGL versions (at least in fonts and the position of UI elements, but not only)
However, I do not know exactly what configuration you have, if your Mac does not have a discrete video card or it is not used for playback, then there may really be problems. As far as I know, only the top 15" models of MacBooks are equipped with discrete video cards, and if this is really standard equipment with an integrated video card from Intel (for example, some Iris UHD), then there will be only 48 shader processors there - this is slightly more powerful than the GPU of a mobile phone, and somewhere in the level of video cards between 2005 and 2010, and this can cause problems because and heavy pixel shaders are very actively used in this game (postprocessing and some effects), although I specifically checked the standalone version on my very cheap laptop without discreate video card and there were no problems, but it was the windows standalone PC version. In general, I need to understand better what your problem is and what it is related to.
