Ill give you some basic video advice in a linear order based on each section. Right off the bat, the video is 16x9 but the game footage is 4:3 leaving you with ugly black bars on the sides. This makes the video look very unprofessional. You would be better off creating some sort of frame thats branded and ties directly into the games aesthetic to go around the footage. Here is an example.
This particular video has the same footage running underneather blown up and blurred with its opacity turned down so its not distracting. Its also desaturated with the purple stars, a theme found throughout the game overlayed to really make the video in the centre stand out. This serves the dual purpose of filling in the 16x9 frame while re-enforcing the games branding. Not many RPG maker games do this, but you shouldnt be looking at what your competitors are doing and saying "they do it so its good enough for me", you should be saying "they are doing it but I am better than that and I am going to stand out from the crowd".
Next up we have the way your trailer uses text.
The text "Unlikely hero" is just dumped at the top of the screen. I know this is to keep it out of the way of the slimes conversation which makes sense, but really theres no reason for this text to be overlayed over the game footage at all. Rather it should be on its own clip as a title card.
By having title cards you keep the text nice and easy to read and viewers arent forced to have to choose between reading your headline and the dialogue between your characters. Also what you currently have written is gramatically incorrect. It should read "An Unlike Hero". Keep in mind that its not a full sentence, so you can capatilize each of the words which helps gives it presence. If the trailer has bad grammer in it potential buyers will be wary of the game itself as well.
There is then a star wipe which, okay, nobody should ever use a star wipe for anything, ever. I dont know what video software you are using but the transitions between clips are the biggest giveaways that you dont have any real experience video editing. They feel incredibly cheap and unprofessional. There is also a glitch in the star transition where you see another environment within the star for a few frames, this glitch makes the transition even more jarring. If you are going to continue to make the trailers yourself I recommend upgrading to a professional editor such as Adobe Premier and doing some tutorials.
This is followed by "Transform to Solve Puzzles", the gameplay clip in this section with the goat is nicely chosen and does a good job showing that mechanic. Sadly by the time you have read "transform to solve puzzles" the clip is half over and you have missed a chunk of it, once again, a titlecard would avert this issue. The sequence with the goat is also enough to get the point accross but seeing the character turn into a troll to open the door might set off red flags for a lot of players. "What sort of puzzles would require me to turn into a troll in order to open a door? This games puzzles must be really obtuse, im not playing it." Thats not the sort of reaction you want to draw out of potential customers. Remember, the players dont have context for what they are seeing. Keep clips simple and logical.
This is followed by another stock transition, this one even more glaring than the previous one. If you ARE going to have transitions keep them all the same throughout your trailers. Having different transitions every time makes it look like someone has drag and dropped random transitions into the timeline without any thought.
Next we have "Puzzle orientated gameplay with no combat". Doesn't really have much of a ring to it does it? Id replace this with a title card that has something like "A Purely Puzzling Adventure" or something along those lines to tie into the humour. Its a simpler sentence and it flows a lot more nicely when read. The vines clip is fine, there is dialogue to let viewers know what exactly is going on in the clip which is good. The second clip however is incredibly confusing, I have no idea whats going on even with the dialogue at the end. If your going to show off puzzles try to show off ones that are incredibly easily to understand as a passive viewer even without the context of dialogue.
Sadly that brings me to the biggest cardinal sin of the trailer. It just fades to black, theres no splash screen with the logo or call to action, theres nothing telling the viewer "hey, this is my product, its super rad go buy it". Most trailers have whats called escalation, the music swells as the trailer goes on and then when it hits its peak BAM, this is what the games called, check it out! But here theres nothing, it goes out on a whimper. The call to action is the last thing the viewer will see, its what they will remember, its what sells your product, its critical you hit the viewer hard at that moment.
I know your hearts in the right place, and your right, lots of RPG Maker devs are terrible at marketing, but this trailer shows that you are also one of those people (no offense) and your past success is inspite of your lack or marketing understanding, not because you know what your doing. The stuff I have listed above is super basic high school level marketing. I didnt even start to go into the importance of branding or messaging, which is a huge thing (again, this trailer uses default fonts as well which carries absolutely zero branding for example).
If you dont have time to learn how to brand and edit trailers as a publisher than its your responsibility to find someone that can, and if you take on some of my above advice I can guarentee you will notice positive increases in traffic and sales. I know this is only a budget title, but a publisher is only as strong as its weakest product and everything you publish regardless of size and scale does reflect back on you in a multitude of ways. Its your responsibility to make me care for your product, why should I as a consumer want to care about something that through your trailer it looks like you dont actually care about yourself? I know you published this game because you do care about it, but your average consumer isnt going to know that.
I agree and even said the same but Dustin doesn't have the time to do so.
Thats a shame, but perfectly understandable.