Thanks for your feedback! We're still working on the game, which will hopefully feel a little more reactive. We're also trying to address the slicing issue, but that has to do with something inside of EzySlice library. Personally I haven't really encountered any optimization issues, even on an older laptop without a graphics card, but we will do our best to fix them (maybe change the lighting to baked only, without the realtime shadow calculations?). We hope to release the (hopefully) full-working demo-game (only cave levels) soon.
-bajtix