Hello and welcome to Feedback Quest 9! My name is Hythrain, and I'm one of the hosts for this lovely event! I'm also one of the streamers, so both the game and this feedback are being done live! If you want to see the see the VOD, let me know and I'll link you to it when it's uploaded to YouTube!
This game gave me some League of Legends vibes, and I wasn't alone in this as others in my chat brought up. This isn't a bad thing, just an interesting observation. Are you taking inspiration from LoL by chance?
I want to start with some minor things, which also happened to be the first things I noticed. For starters, when asked to choose which control scheme I wanted, the buttons labelled on the WASD controls were instead WAWD. Not a big deal, but figured I'd catch that for you now. I also noticed that when the tutorial asked me to do a dash, I actually couldn't do one until I did an attack. I also wish that pressing ESC brought up a menu rather than the "Exit Game?" screen as it does, especially since the most prominent buttons on it are "Confirm" and 'Wishlist" instead of "Confirm" and "Back." Going to a menu where the player can choose to go to Settings, the Title Screen, to Wishlist the game or the Exit Game would work better (And obviously, keep the confirmation screen when choosing Exit Game).
Now onto the actual gameplay. The first thing I took notice to was how moving around felt really sluggish. I was slow to start moving and slow to turn, and even my primary attack felt slow going out. While this can be nice for some players, even the folks in my chat who would prefer slower gameplay said it felt too slow.
Next, I feel that the left mouse click skill should continue working when holding the button rather than forcing the player to spam it to keep attacking. Not only does this wear a mouse down faster, but it can become painful for people who have issues with their hands like I do (I'm 41 years old and have had bouts of carpal tunnel in the past year and a half, so stuff like this can really cause me pain if I'm playing too long).
This next one is more personal preference but I think this would be better for presentation: I'd recommend reordering the skills you show on the bottom. Right now, they're shown in this order: Space, Q, Right Click, E, F, Left Click. Instead, make it this: Left Click, Right Click, Space, Q, E, F. This way, you're putting the primary skill first, followed by the secondary skill (right click), then dash, then other skills in order on the keyboard.
I have two more things regarding skill usage, but since I feel the strongest about them I want to make them last. Instead, I have some notes on the upgrades screen.
First, values aren't showing on the upgrade screen. As such, I don't know how strong of an effect each upgrade has, nor do I know how much they increase in rank. I also don't know if Vampirism is supposed to affect all skills or just some as whenever I thought to see if it was healing me, I couldn't see a difference (Showing numbers on the player's health bar could help this).
Next, I caught a bug where if you're moving when the upgrade screen comes up and then let go of whatever buttons you were pushing, you'll still be running once you get off the upgrade screen. I assume you're using a key up function to stop movement, so you may need to change this to reset movement once the upgrade screen appears (or even change the functions you're using).
Last on the upgrade screen, I suggest removing the timer when choosing an upgrade. That way, the player has time to read through everything and can make an informed and well thought choice.
Okay, onto the last parts. Both of these relate to how skills are used. I took note that when using all skills, the character will always use the skill in the direction of wherever the mouse cursor is. For the most part, this is fine. However, I don't think this is a good idea for the dash skill. Dashing it usually used to either get into a group or out of a group quickly. If you're running away but have your mouse pointed towards enemies behind you, dash will send you in. Similarly, if you're running into a group but you've not moved the mouse in yet, it'll send you out. Instead of how dashing works now, simply make it send the player whichever way they're facing. That way, they can control it by facing the way they want to go.
Next, I noticed that all skills besides left click and dash cause a slowdown in the game while you're holding the button for them. Personally I like this effect for the right click skill since you can then move the mouse to quickly change how you're using it, but this doesn't feel good with the Q, E and F skills. The reason for this is, at least for the starting character, the Right Click skill has a movement component to it, meaning it can be used as a tool to escape danger as much as to get into the fight. The cursor is also controlled by the mouse as well, so it's easy to hold it and then move the mouse with the same hand. However, holding Q, E or F require you to take a finger off of WASD to use. Holding any of them doesn't feel natural and it's more likely the player would be pressing these buttons quickly before returning to WASD. Because of this, I think these skills should just be used the moment they're pressed and not have this "hold to slow the action down" mechanic.
I think that's everything I got. Good luck with the game! :)