HOW BIG IS TOO BIG?

File size really doesnt matter.
But about your pictures:
If you can, I would use a Jpg, since your not losing
a noticeable amount of detail, and it only takes about
half the file size of a Png image.

author=LockeZ
Don't ever use jpeg images for anything except photographs. You have no idea what you're talking about. You will either end up with larger files than png images, graphics that look like dog vomit, or (most likely) both.

Sorry if that sounds rude but I need to make absolutely sure that no one skimming this topic for ideas sees your idea and decides to do it. It will singlehandedly ruin their entire game.

Really?
I dont notice a difference when I import resources in RMXP.
But yeah, if you want quality, then JPG will not do.

Rare, you need your eyes checked. jpegs will fuck up your RM graphics something chronic. Also, ogg files. Get rid of things you don't use - sound, music, pictures, etc. Zip that shit up.
Lastly, if it's still really big, offer a double download - one version with RTP, one without. And in the case of movies, split the folder - have one with just the game and one with the movies folder. Offer the player a choice with a simple switch "Movies on/off" that you can choose at the start of the game. This way, any movies that are optional (say flavour) can just be switched off and skipped over in the game itself and people who hate larger files can choose not to download the optional/extra movie files.

Here's the question that begs to be answered... at what point do you say "Meh, no RM game is worth that much bandwidth" and so you don't end up downloading it?

100 MB is absolutely the final last ultimate deadline.
50 MB +: The game has too interest me VERY GODDAMNED MUCH
20 MB +: If the game looks very good
10 MB +: The game has to lock at least above average

author=Deacon Batista

Here's the question that begs to be answered... at what point do you say "Meh, no RM game is worth that much bandwidth" and so you don't end up downloading it?

100 MB is absolutely the final last ultimate deadline.
50 MB +: The game has too interest me VERY GODDAMNED MUCH
20 MB +: If the game looks very good
10 MB +: The game has to lock at least above average

...the fuck? Have you ever played a 10 MB game? That's smaller than an NES cartridge. It's not even possible to MAKE a game that's only 20 MB with RPG Maker, unless you're doing something really bizarre like making the whole game take place on a single screen. My game's 30 minute first dungeon demo would be 20 MB if you deleted all the audio. Did you show up here in a time machine from 1990 or what the fuck is your deal? I utterly refuse to believe that fifteen minute download, assuming you have the worst possible internet access available, is your absolute final ultimate deadline. I'm going to go so far as to say you're a troll, trying to trick people into making shittier games for the lulz.

Well, the only games that require RTP to run are unfinished games. It's only playable by a small subset of fellow indie game designers (or extremely determined players) in that state, so clearly you're not really ready to release it to be played yet, for one reason or another.

LockeZ, NES games are in the KB range, not MB's.

author=LockeZ
OK, you're right, I was thinking of later cartridges. Most NES games didn't go over 500 KB.

Still, that's with midi music, midi sound effects, 8-bit graphics, and really skilled programmers micromanaging the assembly code to compress everything down as small as possible. If you were to make the original Contra in RPG Maker, it would probably be a good 20 MB.

RPG Maker XP and VX games are similar in quality to early PSX games, minus the FMVs. RM2K3 is more like SNES in terms of graphics, but still matches PSX in terms of audio. Most non-rpgmaker indie games are in that ballpark as well. How big are PSX games if you cut out the FMVs? A couple hundred megs?

The idea that anyone would not be willing to wait fifteen minutes to get a game is beyond my comprehension, though. I bet you spent a good hour or two browsing the list of games. I bet if your only criteria were "completed game" and "less than 10 MB" it would take you more than fifteen minutes just to find a game to download, especially on an economy-class internet connection.

Depends what Game Engine they used for the graphics.
According to one source, the Graphics portion of PSX games were a just a tiny fraction of the 640 MB capacity. FMV's and Audio took up the majority of space.

author=Rareware
FMV's and Audio took up the majority of space.

Where have I seen that? (RM games cough cough cough, AceRTPalittletoo cough cough).

Normal games get 80-90% of the total data size from music and sounds. The rest for graphics and even important binary data (DB, maps, executable).
The SNES had some advantages over the RM. First of all, there were no duplicated tiles or graphics. Any console can load any tile at any time (just like VX, but limited only by cartridge space). I think EB had tried to make up for that a little though. RMXP has the autotiles, which compensates a little too, and VXAce forms tilesets from "subsets".

Also there is the lzh compression, which was common at least on the GBA. Most graphics were stored compressed. And data too. Also, I suggest indexing pictures as much as possible. Pixel-art/sprites normally doesn't gets a lot of colors if done correctly ;P, and indexed images have support for "transparent color" too. Unless you need alpha...

Lastly, OGG is a good alternative. MP3 is a good choice for VERY high kbps rates. But OGG is great for lower ones. And by lower ones, I mean ~160. Seriously, tell me if you spot differences between 160kbps and 320kbps using regular speakers (and you need high volume, dunno, play it on the cinema or somethin'!).

The thing is, I think that sometimes people exaggerate. Yeah, why not? everyone can DL some gigs of an RM game. But why your game needs that much data?

author=KingArthur
Would just like to point out that PNG graphics utilize loss-less compression by their design; RM games consequently store graphics compressed.

Ou, you're right. Dunno which is better, if lzh (common in GBA games) or zlib (used on PNGs).

"But" yeah, "we" have "that" (the stuff about bad use of quotes reminded me of Friends xD, "sorry").