Yeah, it's weird, on this machine the non-OpenGL webstart versions run smoother than the OpenGL ones. I run about 1024x768, and the OpenGL webstart versions take up a lot of CPU. The smaller the window size, the less the CPU, so I'm guessing it's somehow falling back on a software renderer.
The non-opengl version doesn't require any 3D acceleration, so it generally runs faster.
It is possible that the OpenGL slowness is caused by the TextureRenderer class I'm using. This translates 2D drawing operations to an OpenGL texture. I've seen that it runs slowly on some machines. However, it should only be slow when scrolling. I tested it on an older apple and noticed it ran at erratic speeds. It was slow when scrolling but reasonably fast (using 3D acceleration) when not scrolling.
Another possibility is that there's a software fallback problem with wrapping NPOT textures with your card/drivers. See for example this forum:
Here's a version where I disabled use of NPOT altogether:
The progress bar at the bottom is not visible when I run the game in fullscreen with webstart.
I'll try to fix that.
Is the game supposed to have sounds? I don't hear anything.
No, sorry, should have mentioned this.