Alright, I'll do as much as I can here while I have some time.
Cadash is a side-scrolling experience-based platformer (in other words, an action RPG). The basic premise of the game is to go rescue a princess.
You are given four characters to choose from, each with their own strengths and weaknesses:
The Fighter has excellent offense and defensive ability. He is moderately agile and gains experience at a decent rate. He cannot use magic of any kind, and his attack range is somewhat limited.
The Mage has low offense and defense with average agility. He gains experience the fastest of all the characters, and he is the only character that can use offensive magic which will eventually become extremely powerful. His melee attack is no better in range than the Fighter though.
The Priest has good offense and average defense. Her agility is rather low, and she gains experience slowly. Her attack range is excellent, and she is the only one who can use healing and protective magics.
The Ninja has average attack and defensive ability, but his agility is very high and his attack range is the greatest, considering he uses shurikens. He gains experience at an average rate.
The maximum experience level for al characters is level 20. Each character gains HP and MP (plus other stats) at different rates.
The gameplay is pretty cut-and-dry platforming with the added twist of experience gathering. Each enemy you defeat gains you experience points, and most also drop moneybags which you can use later on to buy new equipment and items. The items vary from version to version, but there are a couple which are the same in all versions, which are the herb (heals 10hp when you run out of hp) and the antidote (cures poison...becomes VERY important in the 3rd area which is filled with poisonous nasties). There are a total of five areas to conquer, each with different environments and enemies to learn.
Now, for a rundown of some of the differences between the arcade, the PCE, and the Genesis versions:
The arcade version can have two machines linked together, for two two-player teams (four players at once). This isn't possible on the other versions.
The arcade version, being a quarter-muncher, had to have a way of making money, so the game was timed, with the timer being modified when a new world was first entered, or a timeclock was purchased. Neither the PCE nor Genesis versions have this feature.
The arcade version will show you your stats when you enter a door, or when you stand idle for a moment. The Genesis version will show you your stats when you pause. The PCE version never shows you your stats.
The arcade version and the Genesis version allow you three letters to make your name. The PCE version allows four letters, and includes a couple of secret codes.
The Genesis version, as stated before, lacks two characters: the priest and the ninja. The arcade and PCE versions have all four characters playable.
The arcade and Genesis versions have very similar graphics. The PCE version does not try to copy the arcade graphics, which some people like (for example: me) and some do not.
In the arcade and Genesis versions, you could be resurrected if you died; another quarter in the arcade, and a special item in the Genesis version. In the PCE version, if you die, it's game over instantly, no resurrection possible (unless playing 2-player, in which one player can resurrect the other at an inn).
The PCE version adds an additional key to the second world.
Characters gain noticeable changes to their movement speed in the PCE version as they gain levels. This is much more subtle in the other versions.
The arcade and Genesis versions feature hidden items that can be attacked at various points in the areas. The PCE version doesn't have these, but instead has a number of extra treasure chests.
The Genesis version has a bit of censorship in it (the mermaid scene) which is in no way censored in the PCE version or the arcade version.
In the PCE version, the mermaid scales are an item you actually pick up. It is automatically given to you in the other versions without having to pick it up.
The PCE version is missing the Mage's level 20 magic spell.
The Genesis version has the same screen warp effect as the arcade for area transitions. This wasn't implemented in the PCE version, a simple fade is used instead.
The arcade and Genesis versions have the same cheap-looking warp effect on the flames in the title logo. The PCE version uses much nicer looking flames instead.
In the PCE version, huge hits cause tremendous throwback of your character. This doesn't happen in the other versions.
The "mini-me" character (I forget its name) that can be found in the fourth area of the arcade version is missing in both the PCE and Genesis versions. This is a little version of your character that sits on top of your head and rushes out to attack enemies when you press the attack button. It only lasts a few minutes but it's neat.
In the arcade version, all inns get more expensive each time; if you stay at the same inn twice, the second time will cost more than before. The other versions have set prices, although they get more expensive as you progress through the areas.
The arcade and Genesis versions have equipment names in the shops. This is missing from the PCE version.
The PCE version has certain hidden platforms in the final area that are not present in the other versions.
The final boss in the arcade and Genesis versions are alike. The PCE handles this differently. Hard to judge which method is better, but the arcade and Genesis versions have much longer final boss fights.
There are other subtle differences as well (such as the ball and chain statues in the fifth area) and I could spend a day listing them, but these are the major differences that anyone who has played all three would see.
All in all though, the PCE version is an intentional break from the arcade version; it has a lot of features all its own and comes off being a different game overall. It's definately worth getting and playing.
