Momodora III is a 2D action platformer. Similar to the previous game, there is some evil going on around the village and two priestesses are sent to investigate and get rid of the problem. This time you can play as either Momo or Dora. Neither the story or the gameplay changes based on your selection. The only difference I could see was how they look. There are some people you meet along the way (again) but they don't directly effect the story (again).
You attack with a leaf weapon (series staple), hold the attack button to charge a projectile attack, and find items to equip for more abilities.
The level design is more similar to the first game where levels are made to be progressed with an ending to each having a boss. There are a couple alternate paths in one level, but it is mostly straight forward. Enemies drop money and nothing else. There are some items hidden in secret areas and you can also buy equipment from the shopkeeper who shows up in the first 3 levels. You can warp back to previous levels at save points. You save by praying at the bells (you can't hit them anymore).
You get three item slots on your first playthrough. When you beat the game you can save and restart from the beginning with all your items (except a few story related ones) with an additional item slot! I've beaten the game twice and got up to five slots, so I don't know what the maximum number of slots is that you can get.
This game is on Steam and so there are achievements. There are # which you unlock from playing the game start to finish. Four more achievements are unlocked through special tasks and none of them are overly difficult or grindy to get.
This is a very short game worth only the $2 I paid. It takes between one and two hours to play through your first time, although it is easily beatable in under 30 minutes with the right setup. Steam achievements add some more stuff for you to do, but I got everything in about 3 hours. Momodora 1 & 2 are free games that exist outside of Steam, so try playing those first before trying this one out if you're still unsure. The 4th game: Reverie Under the Moonlight, is a much higher quality title: better visuals, longer game, deeper combat, all that good stuff. Momodora 3 is a fine game, just expect to get what you pay for.