Ratzo Rocks has a bunch of upgrades you can buy to increase your winning chance during a battle.
99 Coins - Double Jump - Lets you Double Jump, dodging Barrages and Fake Punches more easily
500 Coins + Double Jump - Triple Jump - An upgraded version of Double Jump.
300 Coins - POW Upgrade - +4 POW.
666 Coins - Demonic Upgrade - Enables you to use your soul for a fight when you are at 0 HP, continuing the fight.
0 Coins + Defeated Sandlord - Upgrade Slot+ - Gives you +1 Upgrade Slot.
1000 Coins + Defeated Obsidirock (Optional) - Holy Upgrade - x2 to Demons/Corrupts. Gives you an advantage against C2+ Bedrock.
99999 Coins + Defeated Maelstrom (5th time) - Ascend - Enables you to Ascend, giving you 100 Ascension Tokens, but reverts your stats to Level 1 stats.