good, i hope the sequel is better
not a bad game, i like the different types of bows and arrows, however the lack of music or a good story that could be easily inserted makes the game repetitive, plus trying to get the best bow as quick as possible by not spending on arrows or other bows, makes the game too tough in the later stages when they are vital.
rather then force the player to change their style of play, have the enemies drop arrows when they die to make it a little easier, and keep up the pace of the game. trying to kill a boss for 20 mins and then die becuase you didnt buy a new bow or upgrade it, becuase you want the best one is really annoying. you could also try ressurection potions, so that the player does not have to start from the beggining again and putting the player off playing it again.
that aside, i think the achievements, variety of enemies, weapons and ammo are definiate plus points, tweaking this game by adding images to go with the story, possibly some music and slightly better game mechanics would push this game foward.
a good idea would be to have unique pieces of music for each of the bosses and a different piece for the battles before the boss, along with different maps, and unique maps for each boss. a couple of cutscenes not neccesarly animated, would make a big difference in the game.