This game was so fun!! The art is so cute, the music had me bopping my head the whole time, and the controls were so smooth. I can tell how much work you put into this. I found the dialogue amusing, and the premise of the game sounds interesting. I wonder who the big slime was. I'm quite excited to play this game when it's fully done!
If I were to give feedback, I noticed the sword respawns if I die and respawn at save point. I could pick it up again but I didn't notice any bugs caused by this. Also, there is no feedback when attacking big slime (not any that I noticed at least). A sound effect or flashing sprite would help convey that the player hit the right spot, but that's something for the full game I suppose.
The only other feedback I have is that it was very short and I'm upset that I cannot play more. The level design was well executed and suits the metroidvania theme extremely well. Honestly amazing job. Keep up the great work!