I played the demo way back when, and thought [title]. I play the fully fleshed-out game, and my stance is the same. The game is more developed overall, but most of the changes were not for the better. The concept is that time advances when you move, i.e. if you stand still, time stops; if you move, time moves. This could be used make a neat puzzle-based, slower-gameplay shooter.
The game doesn't play well. The maps are all very small, and many are spattered with enemy spawners which aren't even remotely hidden, which means you can get an enemy spawn right next to you. Enemies spawn almost instantly, which means you can look at a spawner, turn to shoot, and in that time, have a guy spawn behind you and kill you. Now, the obvious solution to this is to not stand near enemy spawners, but some maps they're everywhere, and so an area you think is safe can becomes hostile almost instantaneously. Now, since the game should be a take-it-slow kind of deal (you have as much time as you want between actions), this should be fine, but 1) time moves while you look around, so you can't do it while confronting another enemy, and 2) being careful like that isn't fun in Superhot- there's ways to make a game challenging without having to resort to random enemy spawning. That said, not all levels have enemy spawners, and some actually have logical enemy spawning. Another issue with the game is that the gimmick is often unnecessary. You can dodge bullets, but you can also (and it's quicker) to just hide behind a wall, like in any other FPS - you need to wait for your gun to reload, anyway. The game does force you to use it by making your movement speed high, meaning there's no intermediate speed, so you can't move without having to tap a direction to make sure you don't get shot, which is just annoying.
The game makes a lot of bad decisions about how it presents itself. You start the game and it boots a DOS-inspired menu, which is completely out of place for what the actual game is. There's useless options which I guess are jokes? The game kicks you back to the menu at times to trap you into story bits because they couldn't fit them in the main game. They could have put them in text boxes in the game, but I'm glad they didn't, since their idea of a "text box" is to display huge text while flashing and warping the screen. They can only flash two words at a time, so to display even a mid-length phrase, the screen needs to flash several times. The game shows you text multiple times during a level, as well as whenever you get a headshot or whenever the game wants to, and it's as obtrusive as it sounds. At the end of each level (or when you die) you get the narrator repeating the game's title (annoying) while the screen pillarboxes to 4:3 for no reason (oh, they also put a pseudo-CRT bulge which warps the screen, really annoying). The one nice visual effect is that people and objects break into pieces when destroyed, but when this happens the framerate tanks, and that's unacceptable.
In the end, the most fun you'll have with Superhot is when you're actually playing the game (and not during a forced story bit) and are moving quickly, which means you're not actually using the game's mechanic. Maybe the concept is neat on paper only...