That is odd. The game had worked in every mobile system we tried it on. Problem may be with your security settings. Be sure to enable the use of third party executables. Other than that I don't know what the problem might be.
Yeah this is very strange, ive had zero issues with other apk files from this site, and have double checked my permissions. It still says can't open file when I click on the file from my downloads. Something strange is happening and I'll just have to dig around more and see if I can figure it out, because the game sounds very interesting and I'd love to play it.