Surprisingly fun, all things considered. I played the original No Time to Explain flash game when it was still fresh, and honestly found it to be pretty boring. And truth be told, I'm very critical of games on Steam that seem like they'd be better suited to Kongregate or my phone (Snuggle Truck, I'm looking at you). All that said, I really enjoyed this much more fleshed out version of No Time to Explain, and it gets a pass from me as a game that fits right in in my Steam library.
When No Time begins, you're minding your own business, dancing like a dork in your living room. When without warning, a version of you from the future appears, states the game's title, and is promptly grabbed by the giant, mutant crab that smashes through the side of your house. Future you drops his... rectangle thing. This gun (as it turns out) shoots a blue beam which delivers enough thrust to propel you when wielded properly, and just happens to be the core mechanic of the game. You run out across the hills, jumping through portals to different times and dimensions, defeat the crab, and rescue your future self. And the game is underway.
The thrust gun takes a little getting used to. I've heard complaints about the physics behind it, but honestly I never had much trouble controlling it. Just gotta point in the right direction, and remember to jump and thrust at the sameish time for maximum lift. You'll get the hang of it, soon enough.
The overall difficulty of the game jumps around. There are some parts which are rather frustrating, but luckily you can start over right where you just were most of the time. Respawning is weird in this game. Typically you reappear standing on the last safe surface you were on before you died. This can make some boss fights laughably easy as you stand in place dying repeatedly but instantly respawning in the same exact place as you fire your gun continuously at the weak point. At times, though, you can die in ways which will restart the level. This typically happens on the more puzzle-oriented stages, or when you stay on fire or sizzling with acid for too long. Stage-reset deaths are featured in certain boss fights, as well, so you'd better figure out the tricks to staying alive if you hope to make it through.
The thing I love most about No Time is that it's constantly trying to reinvent its gameplay. Sometimes this just involves a new mechanic, like catching yourself on fire to burn down barriers, or flying along blasting dinosaurs in a shoot 'em up segment. Sometimes it involves completely replacing that central thrust gun mechanic. In one memorable bit, your thrust gun is replaced with a powerful shotgun. In another, you have no gun and must use psychic powers to fling yourself along. My favorite part is the "video games are art" dimension, and I'll leave it to you to wonder what that's all about.
The humor is decent enough. The game is weird, the plot manic, and the characters lovably un-self-aware. There are a great number of hats to collect across probably most of the game's levels, ranging from basic, to silly, to bizarre, to completely nonsensical. These are usually more than just a simple hat, often transforming your head entirely. Hats offer no gameplay advantage, but the variety is such that I'm always excited to see what a new one turns out to be. Some are pretty well hidden, or tough to get to, too. So they offer decent replayability, if you decide you gotta catch 'em all.
I had fun. At the time of this writing, though, the game is actually really glitchy. I encountered numerous glitches on my way through. None game-breaking, but some strange visual errors and general choppiness cropped up now and then. As I hear it, this is because the devs are in the process of updating the game and transferring it to a new engine. This update will be free to anyone who already owns this version of the game, which is nice. So it's up to you whether you want to grab it cheap now and have the new version when it comes out, or just wait and get the update. But I do recommend one of the above.