Not perfect, but I like it
This is a fun game! There are a few bugs (like the money bug that everyone mentioned), but I still find it enjoyable.
A few tips I found helped out with getting through the game a bit easier. (at least, the first time through. Haven't tried hardmode yet, since I want to get mage's apprentice before beating the game the first time)
First off, try and feed your dragon constantly. Get it leveled up to its max and the rest of the game is cake. Bosses that would usually destroy you can barely even lay a finger on you, because of the Dragon's claw attack. HUGE knockback!
Don't bother buying food. Just farm it from the early levels. Get the mage her Nova attack and go to the stages that start you off with a few enemies surrounding you. (Blob Bonanza or Level 8) With Nova leveled up a couple times, she can wipe out everything around you in a couple waves. Then just pick up any scattered items left behind.
To level quickly, refight bosses and sub-bosses. They give you WAY more exp than just grinding regular levels over and over. Just revisit the last boss you taken down over and over until you level enough to fly through the next few stages to the next boss. The only real exception to this was when I got up to my late 30s. Then I started just grinding level 2 of The Training Grounds. (you can make TONS of cash on this stage by farming it over and over. I turned on my game with 00 gold and made 5000+ with not too much effort)
Like I said, its a fun game. A few bugs that need to be sorted out, but so long as you can figure things out, it shouldn't be too difficult to fly through on your first play through.