Hi,
I'm interested in RWR and before buying it on steam I wanted to try the demo on my PC, which is an ultrabook, CPU intel i5 3117U , GPU Intel HD4000, RAM 8 GB, running Kubuntu 14.04 LTS. I did not install any GPU driver.
( I know it's not an ideal gaming configuration but for now i'm stuck with this pc, which usually allow me to play some indie game at an acceptable resolution and performance)
The PC is connected to an external monitor (24" FHD) via HDMI. Only the HDMI monitor is enabled

The demo starts, but in the menu the pointer is very laggy. I wasn't able to measure FPS but i guess is very low, around 10 maybe.
I tried to lower the resolution to 800x600 and set almost every other field to off or low but the situation hasn't changed. I tried running it both in Windowed mode and Fullscreen.

What can i try to improve the performance?

This stuff might be useful
viewtopic.php?f=5&t=1922
viewtopic.php?f=5&t=1766&p=11555
viewtopic.php?f=5&t=1944&hilit=xubuntu#p11800

I think the old libz lurking in the demo package can cause a software renderer to be used which kills the performance.

Thank you very much!
Deleting the old library worked for me