Great idea, great gameplay. Sounds and graphics are great. This game would be a total 10, however... the upgrade system absolutely destroyed it. It simply takes too long to buy the upgrades, and their improvements are just not worth it.
Why is this mistake so severe? Simple. The player simply can't enjoy the full potential of the game if he can't progress. And let's face it, few people have the time and enthusiasm to spend hours on the same task for no noticable reward.
I, for instance, consider myself a good medal hunter here on NG, still I couldn't take it.
Now the good news is that this may be a very easy fix for you. Either make upgrades cheaper or put some more coins out there, otherwise people wont be able to enjoy this (which is a shame, because, like I said, this game has everything to be a front page here).
Keep it up man!
The gameplay is decent, and I like that you can loop around to collect all of the coins etc., but the upgrade system needs looking at.
It takes an eternity to buy upgrades, and then the majority of them don't really alter the gameplay in any significant way. If you want people to work for the upgrades, then the game needs to keep evolving when you buy something new.
The new planes are pretty, but the only difference is that they go higher. This is mostly worthless.
The other upgrades are barely upgrades at all- the speed up at the start gets me killed as often as it helps, and means I miss a lot of easy coins, while the coin magnet is largely worthless and actually doesn't work very well. More expensive upgrades take hours and hours of grinding to get.
So I enjoyed it for a short time, but I'm now bored and have no desire to get most of the achievements through hours of grinding. Alter the upgrades so that they are genuinely beneficial (allow players to use them all at once for a start!), and make it easier to get lots of coins/make upgrades cheaper.
good games. but it kind hard.
I Really hate dat homming missiles...
if i don't make tricksm they appears in really early like 350M... pretty annoying to be honest :P
Takes WAY too long to gather coins to buy upgrades