Every fight you complete, whether you win or lose, will earn you skill points, which can then be used to unlock specific abilities or attacks on an ever-expanding skill tree. The plot is a bit light but its ability to send up just about every major action movie of the 80's and 90's is almost unparalleled. Add to that the charming blend of chiptunes style music, and 16-bit style graphics, and I think it certainly nails the time period aesthetic it's going for.