Bitshift's advice is hard lessons I learnt during my own playthrough. In general, most combat can be done by using your special attack that'll hit three enemies and watch who gets hit twice, basic attack them, and special attack the remaining ones. Almost all enemies only need three hits so there is some RNG involved. If you face four or more, time to eat the L. That's right, the Lettuce out of a hamburger that'll heal you for ninety percent of your health. Do not waste the hamburger, because the larger gangs of hyenas will enjoy laying waste to Mezz's health bar.
Some fights involve strategic use of guard, others involve trial and error (eg. ambushes) so prepare to save often after a fight. Especially after you pause, check skills, and use 'patch up'. Otherwise you'll just waste time having to heal over again. The game despite it's humble 0.5 version number at the time of writing, is a marathon and not a quick sprint so my advice is to take it slow. Explore, don't be afraid to double back and get the lay of the land. The game is generous and gives far more items than what you need to win the game.