Thank you playing my game and for your comments. I will do my best to address your points.
I am aware and would like to improve the responsiveness of picking up power ups. I had to choose between ones that stayed on the screen forever and ones that disappeared after a time but relied on checking over and over to see if you were standing on its square. I largely preferred the dynamic of having to choose to sometimes risk danger or even voluntarily take a hit in order to grab the power up that allows you to ward off a larger danger encroaching nearby.
Most of creatures attacks are based on RPG Maker's built in Event Touch trigger. With only a short time frame to make our games, exploring alternative collision detection methods just wasn't in the cards for this release.
Save/heal points were placed in shops because they are pretty much the only safe areas. Grinding isn't required if you free the souls throughout the game unless you really want to get them early. I wasn't expecting anyone to do this in a game that designed to be completed in under an hour though. The direction I tried to lead players down was exploring the maps and freeing the souls to get money and pushing forward once you were done with each map. If you want to forgo a lot of the weapon and armor upgrades, you can push right through but the later areas and bosses will be more challenging (but not impossible). I also chose shops for the save points instead right in front of boss rooms because it makes you journey a distance and possibly be down some health before fighting the boss. That's were the fear of a game over was designed to happen.
Certain terrain features signify where monsters spawn from...
Slimes - small holes in the walls
Bats - Larger cracks
Skeletons - Human bones
Ghosts - Coffins
... etc. There are some places on the bottoms of maps where these visual queues aren't there. I tried to limit the number of those.
Yes, randomness has its disadvantages at times. Some designers choose to remove it completely. I tend to favor it because it makes replayability more enjoyable and developers have to replay their games a lot. If I play my own game a bunch of times and know where everything is going to be and when everything is going to happen, I get bored and have a harder time assessing if my game is still fun (to me, at least). For me, fun is the most important aspect of a game and the thing I shoot for most.
I understand that no one wants to run away from enemies but I believe that games like this need some challenge to be fun. There are lots of opportunities to just mow through hoards on monsters but then there's times that things heat up a bit too much and you need to reposition yourself on the battlefield. That was the balance I was aiming for.
You are sending the souls to Heaven, where they would have gone by now if not trapped. That's what the pillar of light represents. The black tentacles meant that those beings just got sent to Hell.
These responses are purely my points of view, design decisions and concessions made to save time. I went into this project knowing full well that it would difficult to create an action game with RPG Maker and knew that it wouldn't be everyone's cup of tea. I'm not saying that you are wrong or anything. I respect and honor your thoughts and opinions and am thankful you played my game and took the time to share them.
And hey, for as many grievances you listed, I'm happy you still liked it enough that you played through all the way to the end. Thanks again and take care!