Thanks for the feedback!
The dash doesn't go towards the boss, it dashes the player towards the mouse position. But this is confusing I've found and it will likely be changed post-jam to dash towards where the player is moving instead since that's more readable.
Also I do plan on adding more bosses! The slime is supposed to have attacks that are randomized each time with new attacks to make it fresh, based on what upgrades the player currently has. But unfortunately the randomizer broke. It's also something I'm fixing. (The palette's were ones I use for low-color-palette games and took substantially less time then boss design, less than an hour to implement, hence there being palettes haha)
Again, thank you for playing and for the honest feedback. I've noted it down for the next build of the game!