well ill give u an 8 for effort.. im a huge physics game fanatic so this would generally be right up my ally tho i have to say there is little to no challenge here.
mainly because pretty much every lvl i played u had jet engines available and all u had to do was make 1 line of wood.. add 2 jet engines a fuel tank and fly to the goal. there was no challenge with obstacls.
for ur next game id say limit the tools and equipment available so wat u are given is all u have and u have to carefully craft a vehical to reach the goal.
or even give the player a set amount of money per lvl so they can only take a certain amount of stuff.. so jet engines would cost most where as piston engins would cost less etc etc.
maybe add in different structure materials also, when playing this i got to the lava lvls and all the stuff was too repedative same engins same wheels same structures same tactics. so ill say what i personally would like to see if u are making another.
1. make a bigger map and remove the screen.
2. add in a currency so the player is limited to what he/she can buy so as to not make the lvl too easy.
3.add in stats which would include weight of finished craft and also the power of the engines
4. allow the crafts to break upon heavy impact
5. introducing new and stronger more exspencive materials to reduce possibility of craft breaking ( possibly unlocked thru an upgrade menu )
6. allowing the player to unlock new equipment using currency which he/she has earned by creating a cheap craft.. ( 1000 credits per lvl.. craft cost 600 = 400 credits goes to players bank for upgrades)
7. and probably the last thing i can think of :P records that can actually be beaten.. 1.8 seconds for a 25 second lvl? come on.
u have the making of an awsome game here and i cant wait to try the next it just needs a few more tweaks because at the moment it doesnt grab ur attention to play for very long as there is no challenge