The dev actually included a guide and some tips to get the good ending as a text file. I'll post the translation here
●Strategy Tips
・When your Fortitude decreases, Lizashia suffer a debuff to her stats . However, Fortitude fully recovers at the end of each day. Therefore, prioritise hiring adventurers over using Fortitude recovery items. Particularly on Day 1, defeating slimes alone will net you around 3000G, so hiring a suitable adventurer will make progress significantly easier.
・Quests from the woman in the top-left of the map and the soldier near the entrance reward weapons. Both provide weapons stronger than your starting equipment from day one, so actively complete them. The quest from the woman at the grave involves fighting three goblins. You'll struggle to win unless you reach around level 7 and have at least one healing item.
・Monsters beyond the swamp drop items with higher monetary value, so aiming for the swamp early is a sound strategy. The quest from the old man at the town's far right consumes 3 action points but yields monetary rewards and an attack power boost. Using your initial funds to purchase an axe or spear for 1500G can also ease the early stages considerably.
・Hired adventurers start with torso armour, so purchasing head armour alone is sufficient for combat. Higher-cost adventurers possess higher starting levels and better stats
Some of my own tips
・Do the quests of the dude at the inn ASAP. He gives accessories that heal you every turn. One quirk of the RPG maker engine is that these items also heal you as you walk around. That means you can always be at full health for every fight
・Once you can beat goblins or mandragora, buying coffee to get the energy to fight them becomes a net positive in cash, so it's worth emptying the Cafe's stock every day. That said, you might want to save them for the swamp area mobs instead.
・There's a mimic in every map and they drop decently strong defensive accessories. There's also an elite mob, with the first two map's (a cockatrice and an orc) being optional. The third map's isn't optional but gives a very strong armor.
Ending Conditions
・Happy End: Beat the Chimera without seeing any H-scenes
・Normal End: Beat the Chimera having seen at least one H-scene
・Bad End 1: Day 3 ends without beating the Chimera
・Bad End 2: Watch all of the H-scenes on Day 3
・Another End: Beat the boss of the swamp (Sahagin) by Day 2 without having seen any H-scenes. Then talk to Volk at the shop. He'll give you a bunch of elixirs for free and set a flag that will trigger an event when you sleep. Choose to go out during that event. Then defeat the Chimera on Day 3 without seeing any H-scenes.
