Personally I did not have a problem with bosses. The first one is simple, she attacks after certain amount of time. Usually after 2-3 hits, then dogde.
The second boss is more interesting as he fixes the issues you mention and there is 1 more attack for you (down + Z)
but yeah, shame that many devs do the: lose to unlock gallery... thats why a really like princess reconquista or kunoichi sekiren
and the economy... to get the 1. 3000 essence is so easy. pickup few mushrooms, grapes, sell and you can have 3000 in no time
in 1.6 the town offers you more items and you will need the heals for the 2nd boss. If you dont get mad and just rush him as fast as possible which can last merely a minute