Snes was indeed state of the art
Short Tech Specs
CPU type: 65c816 (16-bit)
CPU speed: 2.68 and 3.58 Mhz (change able)
RAM memory: 1 Mbit (128 Kbyte)
Picture Proc. Unit: 16-bit
Video RAM: 0.5 Mbit (64 Kbyte)
Max resolution: 512 x 448 pixels
Colors Available: 32 768 colors
Max colors at once: 256 colors
Max sprite size: 64 x 64 pixels
Max sprites: 128 sprites
Min/Max Cart Size: 2 Mbit - 48 Mbit
Sound chip: 8-bit Sony SPC700
Sound channels: 8
Effects and Techniques
The SNES is a truly wonderful little machine, it has many different "hardware modes" like rotation, transparency, scaling that helps the games to scale and rotate sprites. Hardware modes are special routines that are programmed into the SNES hardware that helps the SNES to make all the great effects in the SNES games.

With the SNES´s many hardware modes and it´s powerful CPU and PPU, it can
easily create huge bosses like this..
Rotation

Before the SNES, in the days of the NES rotation was hard to do because in order to make a smooth rotation you had to make an animation consisting of a large number of frames - the more frames the smoother rotation! Unfortunately that takes up a LOT of valuable space. Now the SNES can rotate the sprite all by itself in realtime which saves lots of valuable space. Rotation is for example used when Bowser turns around with his Koopacopter to drop a ball on Mario in Super Mario World. Rotating can also be used to create courses like the ones in Contra 3 where you see the action from above and the background rotates when you turn around (course 2 and 5).
Scaling

A very good example of scaling from the awesome Contra 3 where a airplane flies right towards the screen and bombs the ground.
To scale a sprite means that you resize it, making it bigger or smaller than it originally was. If you start with a small sprite and enlarge it will become rather "pixely" after a while. But if you start with a big sprite it won't happen so fast, though it consumes quite a lot of memory. If you would like to do scaling on the NES, you would have to make one frame for every scale step, so this is not even thinkable if the sprite isn't very small!
Transparency
The great thing with the SNES is that you can make backgrounds and sprites semi-transparent. An example is: the mist outside the ghost houses in Super Mario World. Transparency makes many amazing effects possible like clouds, laser, rain, fire, and water effects.
Mode 7
The SNES has seven different "states" to work in and the seventh is the most spectacular because it lets big backgrounds be scaled and rotated to create impressive 3D illusions like flying over a landscape in a plane. This technique is used in many great games for example in F-Zero, Super Mario Kart, Pilotwings and Secret of Mana (when you ride with Flamie!). Some of the these games uses the additional DSP chip too.
The Sound System
The sound chip (Sony SPC700) which actually a separate processor is a 8 bit sound chip with a 16-bit program counter, but all of it's registers are 8-bit. Even though it is a 8 bit chip it doesn´t generate more than 4-bit ADPCM sound data. It has 64Kbyte memory and 8 stereo channels.
The C4 chip Game cartrigde built in chip
This is a special graphics chip, used to create better semitransparent graphics effects (eg. Rain or water) and 3D effects in Mega Man X2 and Mega Man X3. They are the only games that use it. The chip is was developed by Capcom.
The SA 1 chip Game cartrigde built in chip
This monster of a chip was developed by Nintendo for multiple purposes. One of its tasks was as a memory compression chip, allowing the games to be bigger than normal by compressing the data. The chip also stored supposedly 1/4 of the video game itself on it so people could not copy the games or use them in a copying device. The chip is also a second trimmed down (I believe) version of the SNES main cpu.