...what is with you people? Didn't you read the title of the thread? This is "SNES to GBA ports that aren't good", not "SNES to GBA ports that contain slight annoyances".

Yoshi's Island is not a proper candidate, nor is Final Fantasy VI Advance. In fact, those are two of the best SNES to GBA conversions.

Contra III EX on the other hand is a good choice for this thread as the ability to wield two weapons at once was removed and the game suffers from all sorts of consistent slowdown.


Maybe you guys had unrealistic expectations of the GBA?

Here's some shocking reality checks for you guys:

The Sound

The 8-bit Sony SPC700 of the SNES has a much softer, muted sound and also more musical note range than the Dual 8-bit DAC of the GBA. The GBA can produce much cleaner, higher quality sound effects and voice samples, but when it comes to music, the GBA cannot go toe-to-toe with the SPC700.
Playing to the system's strengths, many SNES ports add voice samples where there was originally none. This was done to enhance the games. Personal opinions as to the validity of that aside, doing that does not make any SNES port with voice samples 'bad'.


Therefore, when *gasp* SNES games ported to the GBA don't sound as good, it's simply because the GBA cannot produce the same audio as the SNES. It has nothing to do with the quality of the port itself.

Colors

The original model of the GameBoy Advance was not backlit, using the same reflective TFT screen technology of the GameBoy Color. Without it's own light source, GBA games used oversaturated colors deliberately and some changed backgrounds entirely to make things easier to actually see when using a GBA. In 2003, the frontlit GBA redesign, the GBA SP came out, allowing games to be far easier to play without a constant external light source. It wasn't until 2005 with the GBA SP 2.0 and the GameBoy Micro that the GBA was actually properly backlit.

As a result, anyone who complains about SNES games to the GBA's colors is not considering the challenges developers had when they made the games to begin with. Sure, Castlevania Circle of the Moon for example might look great on a GBA SP 2.0, or the GameBoy Player, but try playing that on the original non backlit model and you'll see why developers learned from that.


Screen size

The GBA's resolution was 240×160 pixels. The SNES had several resolutions, but typically, games were 256×224 pixels. Converting SNES games to this new resolution, concessions had to be made and sometimes HUD's completely redrawn. Complaining about stage layouts of SNES games on the GBA screen is completely unfair, and again, speaks nothing to the quality of the port itself. It's simply using the screen it has.


All I'm saying is that criticisms brought up so far are mostly about the hardware, not the games themselves.