Needs some polishing
I'm not sure the end result was worth the amount of effort...
The concept is good, and the choice of all the stuff is good, but ring count seems somewhat random, and apart from obvious things (boosters, shields, etc.) it is difficult to know what is the effect of the upgrades. Also, it takes a really lucky run to get anything over 20 rings, so getting the first items to upgrade your ring count was really long, sometimes for no significant/consistant results.
Also, why did some characters cost more? they did not go any further, and did not seem to increase anything...