Fun game, but can be really frustrating, so best played in short bursts. The SURVIVED (i.e. You Win) screen tells me I played for 114 minutes and died 433 times, but it honestly felt a lot longer than that.
This is one of those twitch/punishment platformers, though it's not exactly a platformer since you control a floating ball that can move about freely without worrying about gravity. The goal is to make your way to the end of each of the levels without dying. There are no checkpoints, and but the levels is pretty short. Unlike other twitch platformers, you have a healthbar and most hazards will not kill you in one hit - being squished between moving walls/ is the common exception. Your health also decreases over time, so it serves as an implicit time limit even in the relatively few levels which don't have a huge moving wall (or Boss) chasing you. Boosting (i.e. "running") makes the health decrease much faster, so it's best used only when needed.
Each level has collectible "krebs", and getting all of these greatly increases the challenge, but they are only useful for high scores and achievements. After the first few levels, I stopped even trying collecting them all and focused instead on just surviving.
The game is HARD, and controls take a lot of getting used to. The keyboard offers the most precise controls, but unfortunately a bug keeps you from being able to boost (speed up) while moving diagonally up-left, which makes a few levels impossible. So yeah, that's definitely a minus. But the rest of the game makes up for it in my opinion. The gameplay, though frustrating, is still fun, I found the retro graphics quite nice, and the soundtrack is great. After finishing it, I spent some time going back to a few levels to unlock some achievements, and see myself coming back over time to unlock more.