The following is a reader-submitted review by ducttapeDJ:
Nitrome has really filled a niche. It's a niche that's been open since the Nestle-sponsored Willy Wonka promotional website stopped hosting clever shockwave games featuring their line of original candy products. I guess I think of Nitrome as the Willy Wonka of flash games, since they've got a similar strategy. Take a game that's been done before, add some peppy visuals and music, and toss in a few creative mechanics for flavor.
For example, take their newest title, Test Subject Blue. Start with a platformer, set it in a laboratory, and add some momentum-conserving portals. I bet that's never been done before! Actually, the portals are stationary in this one and you get a real blaster that shoots stuff. The core mechanic is clever, and you'll want to think back to games like Nitrome's own Fault Line for an idea of the sort of mental hoops you'll have to jump through.
Originality aside, the game has the same standard of quality as you'd expect from Nitrome. Great visuals, cool music, and the gameplay would be perfect if not for that one nagging detail. So what's the "one thing" with this Nitrome game? Accuracy. The jumps are unforgiving and sometimes require you stand on the edge of a portal, the blaster sometimes delays a second before shooting and it's hard to predict the timing in mid-air shots, and I still don't know how to tell how close I can safely get to those landmines before they explode.
If you're willing to try, try again to work out the trial-and-error of unforgiving jumps, you'll find 25 well-designed levels that gradually introduce all manner of additional puzzle mechanics, like enemies that must be shot through portals or switches that allow you to turn off the portals for a second and jump past them. Everything in this game is color-coded, too. Orange things kill you, green things don't. This color-coding is slightly misleading at times, as it's not obvious that you can shoot the turrets and monster spawners, but later the game acts as if you should have known from the beginning. Also, in one place the game tells you that a certain monster will delay after it ducks, but trying this advice out reveals that the delay actually comes after it jumps. So maybe take the hints with a grain of salt.
Nitrome's been nice enough not to take the "sadistic computer" route for a story in this one, and you'll notice that the title "Test Subject Blue" clearly implies the potential for a sequel. In fact, other than the "sequel hook" itself, the game has no real plot. You probably wouldn't play this game for the story, but if you're like me and can't get enough new ways to think with portals, you'll probably get a kick out of Test Subject Blue.
Thanks to Tobie for sending this one in!