I was going to review it after only playing the first stage in windowed mode, but I noticed the "Distance to the End" counter I realized I hadn't seen it in my play through due to it being cropped halfway out of the frame by the window. I played the game again and was able to see two more levels!
The jumping feels nice. The shooting takes a bit more time to get used to, but that also feels good once I'm used to it. The randomized sayings on death was a nice touch.
The only thing that bothered me a lot was that if the player dies, they are always sent back to the first level instead of the current level. However, that's not a huge set back. People can play through it.
Why did you say "Do not go to the Credits until you're gameplaying is finished!"? I thought there would be some sort of spoiler in the credits screen. There isn't.