hm. how about shields?
and the ability to go right off screen and apear left makes the first boss rather easy.
besides that, good game.. as far as i am
its nice..
but why can i make the most money in level 1? shouldnt i need to play harder levels to get more money for more expensive upgrades?
now i can just play level one over and over again and buy every upgrade.
oh, and a description for the upgrades would be nice. for example what exactly is the advantage of better wheels?