Monster Mayhem Achievements Here is the full list of all 9 Monster Mayhem achievements.Filter Achievement View View Image viewList view Sort by TrueSteamAchievement desc TrueSteamAchievement asc Achievement name desc Achievement name asc TSA Ratio desc TSA Ratio asc Gamers desc Gamers asc Steam order Date won desc Date won asc What are achievement flags? Click to find outApply Unlock all upgradesUnlock all the upgrades upgrades shop. Unlock all charactersUnlock all characters from character shop. Unlock all stagesUnlock all the stages. Reach level 10Reach level 10 in a single run. Reach level 20Reach level 20 in a single run. Reach level 30Reach level 30 in a single run. Kill 1000 enemiesKill 1000 enemies in a single run. Kill 5000 enemiesKill 5000 enemies in a single run. Unlock all achievementsUnlock all achievements.