"Official" Release

Heyo, do you remember me, I'm coming from Newgrounds. I saw your trailer there and even given my first impression on the game.

I played it in my spare time, here's what I've got to say about it.

The premise is very interesting, it's very mature in its tone, kinda reminds me of Tails Gets Trolled and it's got cool dialogues.

Your post mostly speaks about fixing bugs, but somehow I've seen alot of them. I don't hold it against you or your game, stupid bugs tend to show up sometimes at random for no reason even in my games when I double or triple check everything by playtesting several times. I'll just let you know becuz not everyone is a gamedev and not everyone has my patience:

1. Before the game even started I had problems. The keybinding in the settings is bugged AF. It keeps shuffling which keys I've set for what action. I wanted my game to use Z for interacting, X for cancel or running, C for inventory and Space to jump. Space kept switching place with Z and Z kept switching place with X. So Z was running, X Jumping and Space to interact. This was impossible to figure out, so I just decided to edit the game's save file where for whatever reason it stores settings. Consider making a separate settings.ini file.
2. The Z-order is improperly set for one of the Toads in the mushroom kingdom (1 of the very first few houses on my left), so he looks like he's literally walking on the house instead of being behind it.
3. The Z-order is improperly set for the bookshelves in one of the rooms of Peach's castle. Mario and Luigi can just walk on them.
4. Glutton town (or whatever it was called) had 2 NPCs that depending on some story-based event could softlock the game if they were spoken to.
   
   1. The first one was the one near the corn, no matter how many times I hit Z, the dialogue wouldn't finish and give me back control of the game.
   2. The second one was the mayor's assistant,I ran towards him then hit the Z key quickly, but somehow that caused him to get stuck into a loop where whenever I'd finish the dialogue it'd trigger again and again indefinitely.
5. The cutscene for the prince didn't play correctly, it was just a blackscreen for 90% of the cutscene.
6. The collision is inconsistent. The bridge near Peach's castle is the best example, just hold left or right and suddenly Mario will move a bit more than he should've. There's a collision rectangle that only exists for 1 half of the bridge basically.
7. When Mario goes under the slide, his head gets cutoff by the shadows cast by the slide. I don't know how to better explain it.

That's all for the bugs, but I have some QOL requests for you:

1. When the game first starts up. Why tell me to use Fire 1 button? I didn't know what that meant, it'd be better to just say "Press Space to start".
2. Add an objective marker just to make sure I'd not get lost. I paid attention for most of the game, but sometimes I didn't thankfully I figured out what I had to do. The speech bubbles above the NPCs heads would be perfect to fit that role, just give it to only the important NPCs. Right now it's just "there," I always try to speak to anything that looks remotely alive and friendly, so if its purpose was to let me know who I can talk to, it's kinda useless actually.
3. Beef up your game's physics, it feels stiff and barely controllable especially when jumping. It feels like the character will just lock into a direction and move constantly towards it kinda like that awful Mario game made in RPGmaker. It's not nearly as bad as that other Mario game, but it's not all too exciting either.
4. I don't think it's possible to fix that in Clickteam Fusion, but the depth perception is awful because it's a flat 2D game which makes it hard for me to know where I'll land.
5. Also I still don't know if it's possible to stomp the piranha plants, but since the game has wonky jumps for the Mario bros and weird collision detections and the shitty depth perception I stopped after taking some hits. Maybe I'm not even supposed to do that like in the mainline Mario games and their only weakness is fire and the likes.
6. Make both Mario and Luigi equally as worth it. Luigi has more health and jumps higher which is needed in 1 section of that wooded area. Luigi is also needed for a story event whilst Mario isn't ever needed. Mario could deal more damage to enemies to balance it out, but "more" is relative when all enemies are goombas that die in one hit.
7. Make it more clear that the game has a multiple choices system. Just the dialogue box and arrows aren't enough. If anything I assumed it was meant to go back in the dialogue to read parts I might've missed. Normally, a small box above the dialogue box appears in most RPGs to let me choose i want to pick. Hell even it's the default behaviour for RPGmaker. It's not nearly as annoying as the rest since once I learned this was a thing I remembered it for every convos I had ingame.

This could be a great game, there's a ton to it even tho it's only a demo. I like most of the graphics with a few exceptions like the green solid colour for the grass. The music is fantastic, I don't know if you made it because I can say that it doesn't come from any Mario game I know.

Oh BTW, replace the game's name. "Princess Quest" is so generic that just to find your game I have to look up "Princess Quest Itch.io Mario". Not only it's the name of a minigame in a FNAF game, but a buttload of games on Itch.io also use that name for whatever reason. I'd suggest "Mario's Jubilee" or "Mushroom Kingdom's Jubilee", it's unique and it gives an idea of what the game is about.