First off thanks for your long feedback, it means a lot and is really helpfull :)
A dash would have been indeed a good idea !
I think the bug is due to the slime being faster than the player and the attack cooldown being reloading, i thought about changing the slime movement so it only jumps and doesn't slide like it currently does, it would make the dash ability way more important as well...
I'm very glad you enjoyed the game, means a lot, have a nice one :)