As an avid player of Diablo, I enjoy these kinds of games, but I don't think you did yourself any favors by comparing it to Diablo in your description.
Graphics, kinda awkward animations, but the dungeon enviroments look pretty good, and the monsters have enough detail to them. I will mention, though, that the frame rate tends to drop rather significantly, which makes playing it a bit more annoying than it should.
Also, blatantly ripping off the Diablo 2 Town Portal image. Doesn't look quite as good when it doesn't move.
Sound, only the one musical track, only the one "hitting" sound, and some spell sounds. Not really all that pleasant to listen to.
Controls are...odd. It's nice that you tried to put in hotkeys, but they randomly refuse to work. I had this happen with the inventory hotkey, as well as the potion hotkeys at times. No reason, they just didn't work.
Also, using a bow is annoying, as if your enemy moves, you will be unable to continuously fire, and will instead run towards them. A bit of a problem if you're using a ranged weapon. Targeting a specific enemy is also difficult, especially if they're grouped together.
Gameplay, kill things, randomly collect better gear, kill end boss, repeat. Classic character development rules apply here: 5 stat points and 1 spell point per level, to allow you to customize as you please.
The "40 types of equipment" doesn't seem to be true, as all of the equipment seem to fall under sword, shield, bow, boots, armor, helmet, and accessory, and each has a standard level, magical level, and exceptional level, with exceptional being the strongest. Some of them have different images in your inventory menu, but do not change your outer appearance.
The controls make it a bit annoying to play, but not as much as the slow pacing. None of the fights were particularly exciting, and I never had to employ any real strategy outside of, "Run and pick them off with my bow because they're slow". It was starting to grind on me by the time I finished the second dungeon.
There's no shop, or NPCs, it's just you and the monsters. Sadly, this also means the gear you receive is 100% random. I guess I got lucky with good gear throughout, but it also made the game rather boring. I always had plenty of potions, a healing spell, and near-infinite mana thanks to arrow skills costing almost nothing.
At the least, the game appeared nearly glitch-free, aside from two instances: First, after Death, the first boss, there was an invisible skeleton attacking me. I was able to kill it, but not able to see it, which was confusing at first.
Second, at the third dungeon, I wasn't allowed to go in until I went into the area I was supposed to, and then left. I do not think this was intentional.
Overall, it's okay. A bit too slow paced for me, but then again, it is a short game. The main flaws include the framerate and the questionable controls, which tend to be important for these sort of games. You could of included a "Quality" option, which, oddly enough, isn't in the game.
And, yeah, I don't know how much more obnoxious you could of made that Tremor Games logo. Not only does it eat up a good corner of the screen, did you really have to make it shine?
Not unplayable, but also not a blast to play, and it certainly isn't Diablo.