The creator of the game already made a quick guide for starters, very simple to understand:

https://www.zvitor.com/projeto/caveManual.html

But I will also make a quick tutorial here:

The attack button is a basic melee sequence every beat'up character has. No secret here. NOTE: Diana excels at this.

The weapon button is a basic attack using the character weapon, you can spam it (it doesn't consume mana).

The special button is the main skill of the character weapon and it DOES consume mana. Mana regenerates with time and its regeneration rate vary on the character and/or level.

About the characters, there is also a guide from the creator:

https://www.zvitor.com/projeto/fichaDD.html

Some notes:

• As said before, mana regeneration rate vary on the character and/or level. Exploit this as strategy.

• Diana is the only character that has double-jump. And she already has it from the start.

• Movement speed vary between characters. Diana is the fastest and Bobby the slowest (even at high levels).

• Each boss of the game is usually rekt by one of the characters.