Your sprites and animations look gorgeous, dialogue effects and design are magnificent, and your idea with playing as goblin trying to kill humans is pretty neat, but playing this game was so annoying I could not finish it (skill issue on my side probably) so my review is only about part before 3 knights in a row in a wavey corridor on level 2.
So now I will start whining like a little baby about stuff I didn't like about your game.1. I was stuck at the first archer tower because I couldn't see a part of the wall that was meant to represent stairs. I thought you had to kill archer tower through a wall to progress or that I have to destroy the pumpkin to go through a conveniently placed corridor behind it.
2. Player is really slow to the point where moving with my character is painful. Enemies on the other end feel jittery and chaotic (some of them turn frantically at 90 degree angles while others at much more fair but maybe to easy 180) or even unfair at the same time. Even worse about the enemies is that THEY CAN CATCH YOU THROUGH WALLS, it is just a total deal braker for me, I understand that it was easier to code it like that, but there are just better ways to do it, and in this state it is just to messy to ignore. It is the main mechanic so you can't just half-ass it. Also I get that weird dissonance because I am playing as the goblin and normal humans are running so much faster than me? It feels like nonsense from gameplay and thematic point of view.
3. This game is so easy to cheese that it almost feels like an intended way to play, from killing enemies through walls to that dumb stealth ability with extremally long cooldown, thanks to which you can just kill everyone one by one while waiting an exorbitant amounts of time between each kill for that optimized for boredom gameplay without challenge.
4. Level design feels so empty in a contrast to attention you gave singular sprites, animations and dialogue UI it just feels weird and unfinished.
Ok I had my fun complaining, but all this writing would be pointless if I didn't had some ideas how to fix those problems.
1. If you teach the player that for example green (grass) is where you can walk and gray (walls) is where you can not, then if you want to make stairs work you should make them stand out from walls around them, for example add some moss on the steps. For the archer tower I would suggest adding a dirt road that makes a visible path player can follow to make them do what you want them to in order you desire. Remember that level design is where you prove worth of your creativity and mechanics of your game!
2. When you are creating a game you should focus on what players will be interacting the most. So for example if you have annoying grass texture which covers most of the screen, looking at your game would be really annoying! So by this logic you can think about designing player movement. If your game is about walking around with a character you should focus to make it enjoyable. Rest of my complains in this point can be resolved by training how to work in your engine of choice, so in your example problem with enemies turning chaotically can be resolved with tweens or AnimationPlayer Node and enemies seeing through wall with ray casts 2d and polygon shapes. If you want help you can contact me at discord (kspl9999) I will be happy to help you with Godot and game design!
3. The best way to find problems in your game is to just play it as much as you can when you develop it or if you are able, let other people play it (but it may not be an option most of the time) and about that ability remember that players will try to optimize the fun out of the game if you let them, so don't rely on players to make your game fun.
4. Try to spend more time in level editor to make sure you put enough attention to it, because level design represents how good are your mechanics and how fun your game will be to play.
So in conclusion, I like the premise, but gameplay and level design has some room for improvement. Remember that game jams are place to learn and improve so don't take this comment personally, because I am just another faceless internet person you will encounter in your life. Thank you for reading this monster of a comment and have a great rest of your day!