I think I'll answer the questions you raised Daedalus, which was perfectly cool by the way.
Do you think cameos in a fan game are a good idea? Whether it be a minor tongue in cheek reference, or giving said character an important role in the plot?
I believe that it really depends on how individual the game is supposed to be. If the game creator is intending on doing a brand new game, then I think that an important role of an older character may be somewhat of a clash in intention and result. My reference to this would be any of the official games, they tend to have cameo appearances, but they do not usually allow the cameo to have too much of a bearing on the game. Cynthia in Pokémon Black and White is an example. You may battle her and she makes references to the Sinnoh region and battles you. The game developers who are trying to make an individual and new game, and then use the heroes from the official games, it would personally turn me off. I prefer the originality of a whole new experience.
However, if someone were to make a game with the intention to use characters as their main ones, I would rather see that. I feel that if a person is using a bunch of cameo's, they're just facilitating to the lack of original characters they don't feel like or don't have the ability to create. I support small roles in cameos mostly, as opposed to seeing ones from older games have a large role in fan games.
What's your opinion on the authors of the game putting themselves into the same? If it's a minor thing such as what Game Freak does, or making themselves the professor or villainous team leader, what are your thoughts?
I think it's also acceptable if it's a small cameo appearance. Again with reference to Black and White, we see the gamefreak building, like we do in a lot of the games in fact. I think a subtle inclusion of the person such as this is fine. Where as if the game creator purposefully puts themselves as one of the main characters, it may come across as a little pretentious. The thing is, we usually see a little favouritism when a person puts themselves into a game, such as making themselves a champion or something along those lines.
Again it also takes away some of the originality. Although I think it's pretty sweet when people put their friends into the game as trainers and small cameos. Other than that though I rather seeing completely original characters, this is something that really entices me in a game.
Tall grass in towns/cities. What's your opinion on it, and can it be justified properly?
Oh it most certainly can. If there is a decent reason for it there's no reason why it shouldn't be. I think that it would be suitable in professor's retreat for the starter Pokémon or something along those lines. But, random grass as a way to add decoration to the town is kind of off putting and it's not a liable method of mapping in my view.
But to speak about what I think is most important in fan games. I think that a storyline is simply the foundation, I think that this is where all fan games should begin; creating a good storyline. A decent storyline is a way to draw the player in and wish to play the game. With a lot of the official games, the storyline is quite simplistic, but it is the antagonists in which have the depth and interesting qualities and background. I think they are often the backbone of a good storyline, and as years have gone by, they have become more complex an diverse. Which is why I think that any fan game which is including a group of antagonists or even just one or two, should always work hard on their background and how they relate to the history of the game, the region or area. I feel that if a player is going to be going through a region that antagonists smother, and who will be facing them quite a lot, they will wish to facing interesting characters with intentions that make sense in the line of the story. So from there, I think that the story is probably the most important part of the foundation, writing is an important part of a game.
From there, graphics are always going to be an important part of a game. I think that graphics are what a player would look at first. Tile choice and creation is an important aspect of this, the style of the tiles would always look best if it was consistent, same goes for what proceeds the tiles, this would be the sprites and interfaces. Consistency in graphics is something a lot of game developers work hard on ensuring it. So I think working hard on aesthetics goes a long way.
Something I always enjoy when playing games, is good events and lots of them. Cutscenes and simple events alike, all play a small part in drawing the player in. Though it is good to have a lot to do in a game without been drawn into the main plot through predetermined events, I think it supports a game if it can develop a storyline with a lot of good events. This is certainly something I don't often see enough of in games, good events and scripts.
Overall however, consistency is a very important aspect of making a fan game, and I think the best developers work hard on doing this. Whether it be the aesthetic quality of the graphics, or the depth of a storyline, I think that a developer should work hard on making their game consistent in all areas, ensuring that style and quality matches. I think any style can work, so long as it's executed correctly. So it is hard for me to pin down the most important part of a fan game, every gamer looks for something different, which is why I think emphasis is best kept on consistency and not on one particular aspect of a game.