can you be more specific? What's changed?
"Silhouette Mirage was initially released on the Saturn, but was ported to the PlayStation shortly thereafter. The differences between the versions are minimal - the Saturn version has extra background layers and various other details in certain stages that are missing from the PlayStation version, but that's about the only major change. To make up for this, there's an extra boss fight - the Reaper - at the end, as well as an additional ending for beating it. Considering how badly a lot of other ports got butchered back in the 32-bit era - especially 2D games for the PlayStation - Silhouette Mirage turned out pretty damn well.
However, when it was localized into English, there were a number of gameplay changes implemented by Working Designs, the American publisher. Working Designs was known to tinker with gameplay elements, usually to make them more difficult, but they really went overboard with this one.
The very essence of the power draining mechanics have changed. Previously, you could use any of the weapons as much as you wanted - now, all weapons drain spirit power as you use them. To make up for this, when you attack enemies with the same class, you'll replenish your own Spirit meter in addition to depleting theirs. This is actually really useful in certain boss battles when your spirit is depleted, since you can just suck the strength back out of them. Additionally, some of the weapons in the Japanese version were pretty unbalanced, and this seems to be a way to keep players from abusing the more powerful attacks.
Ultimately, however, the changes do more harm than good. Most of the weapons drain way too much power to be useful. It also pretty much forces you to drain every enemy before killing them, and potentially you can expend more energy than you replenish. It also forces you to use the weakest weapons in most cases, since that usually expends the least amount of Spirit. Quite simply, the game is already complicated enough trying to deal with the different classes - keeping track of ammo conservation just isn't fun.
Furthermore, Working Designs upped the difficulty by increasing the damage inflicted by enemies, as well as making all of the items in the shops more expensive. The latter solves nothing - having to stop and cash bash enemies to be able afford upgraded weapons and health replenishments was already somewhat tedious in the Japanese release, but this just makes everything worse."
PS1 version more challenging confirmed!