Fun but pretty simplistic
The game is undoubtedly fun, but the upgrade system and "multiplier" arrow and bow damage makes for a pretty "monotone" game. The game is actually very easy if you constantly keep up with the most recent arrows and use the highest bow available, and with the high bow drop rates you rarely have to even consider buying a bow. During my first play through I shunned buying arrows in an attempt to save up for a new bow. That made the game significantly harder. The only thing I ended up buying the whole game, other than health, was the final bow. Then that bow dropped during the next wave. In subsequent play throughs I picked up the newest arrow whenever possible and burned through the game with ease. The upgrade system for stats has a VERY high curve, that more or less forces you to raise your stats equally, and punishes you for trying to specialize. Money drops become irrelevant about half way through the game, when you can start picking up the third bow off enemies. Its worth about 25 times the silver drops that you can pick up at that time. By the time gold drops come around you can pick up crossbows worth 1000 each. Ultimately the money drops are worthless unless you a) lower the amount of bows that drop, b) raise the worth of money drops, or c) lower the amount of money each bow is worth.
I did enjoy the achievement system, unlocking new armor and such. Reminded me of Amorphous + (great game btw). But some of the achievements don't register correctly. I got the "beat campaign with buying a bow" achievement during the play through that I bought the final bow for example. It would add a fair amount of fun to the game if you put in some more achievements that you wouldn't get just playing through normally. I got well over half the games achievements in my first play through of the campaign.
The enemies are different, but I wish they had more varied attack styles. The teleportation and different styles of ranged attacks are a good start, but it needs more. Enemies with different ranges, enemies that attack from different directions, enemies with different "attack shapes" (open ended cone, close ended cone, straight stab, arc, ect...). Variety is the spice of life.
The games grammar is a little rough, but its not really noticeable outside the beastiary. I would still suggest emailing a beta to a few people who know their grammar to sort it out. It would make for a better presentation.
I really enjoyed it. Not quite enough to make me wanna get all the achievements, but enough to get me to play for an hour and a half. That's pretty good. Now I'm going to go play Amorphous...