The approach of the game is still the same which is good because you need to change it to the will of your clients as you've said.
About the game itself, the graphics are still and will stay good, the different missions are nice to play but sometimes hard to complete, as EX Citer mentioned already. The sounds aren't at their full use but it's still a demo version like you've mentioned. But I'm still missing the water shader but I guess it will be included in the final version.
Great work, my congratz to the both of you
Btw, the German menu isn't that bad for me since I'm capable of reading the language
Cheers
Frazzle