It could have been awesome.
Well, every shooter has some "special feat" that makes it a bit different from other shooters. Here, it's the fact that your ship has two attacks: First, the normal shot which is nothing special. Second, it can fire a freeze missile which freezes certain enemies. When they're frozen, you can (kinda) fuse with them if you maneuver it into the frozen enemies. If you do that, you have a totally new battleship since you get the abilities of the enemies you fused with (special shots & special powers). After taking a few hits, you're back to your old ship though. Which is something you should avoid at all costs.
Why? Because your normal ship, the .... "Garland" (yeah, that's the actual name), sucks. It's slow and can only take one hit before it turns into a pile of space rubble. It's absolutely miserable, however I believe it actually hits harder than most of the enemy cyborgs you can fuse with. Now that's great, right? You have the choice between 1) playing with only 1 life, moving damn slow but being pretty strong and 2) with playing it safe but losing firepower in most cases.
Most of the time, you obviously are screwed if you do not keep yourself fused with an enemy cyborg. Now, this could work if you played the game long enough so that you know enemy patterns etc. , but most likely it won't work as your ship becomes pretty big when you are fused with an enemy (since those enemies have 2x - 3x your size), so you are an easy target for enemy bullets and a few moments of lacking attention can make you lose your fused cyborg (and - in the worst case - the "Garland" as well).
In the last stages it becomes really impossible to maintain being fused. You will have to maneuver through narrow tunnels leaving very little to no space for errors. If you touch a wall, you get hit. And as I said, after a few hits you are back to your normal ship, the mighty "Garland"!!
But that is not the only problem with this game. The next big problem is: The boss fights are mediocre at best. When reaching the end of the first stage, you get a kinda nonsensical text with a scene showing you accelerating to light speed (or something like that, I really couldn't figure this out?!). After that, you are back to normal speed and a kinda cool boss music starts up. Now you surely are a bit hyped, right? But the hype is entirely gone as you see the first boss, trust me.
The game never picks up. The following boss fights are not much better either. The last boss is as anticlimactic as it can get, leaving you with a sad feeling after you finished the game. You know it could've been better. But the developers just messed up. The idea of fusing with enemies is really cool, but that's the only tiny piece of originality within this game. The rest is just mediocre shooter potpourri.
I wouldn't really recommend this game to anyone as it has some gameplay flaws and really really bad designed enemies and bosses. It's certainly not all bad but it really does not stand out either. There are tons of better shooters for the SNES (let's say Gradius III, Earth Defense Force, Parodius, UN Squadron... whatever) so there is no reason for anyone to pick this game up.
It could've been good. So damn good. Shame on you, developers!