Simple, yet.. omg, I played this for 2 1/2 hours?!
WARNING! SPOILERS!!!
This game was extremely well thought out. It's simple graphics hid the very first spike from me, so I died from that. Then when I double-jumped it (a natural gaming tendency) the roof killed me as intended.
This had me laughing, but I'll admit I didn't expect this aspect to persist or have a lasting appeal. It seemed less gimmicky every time I relaxed, or was fooled enough to fall for it again.
Notable examples: (Again, WARNING: SPOILERS!) were seeing just that many stars only to get hit by one at the end of the section, and getting killed by the "Death" in the first sign only to get ready to avoid "Death" again and get hit by "Of" I felt like an idiot, of course, but I'll be damned if it wasn't me and only me that was the fool at that point.
Games designed to kill you at every turn with things you can't see coming also usually suffer from a lack of game play elements. This, also, proved me wrong. Again, I expect the first couple of jumping puzzles to be "In Betweens" for the "Part of the screen attacks you" bit, but they did, in fact, start to get creative and interesting. I was also impressed by how often you had to consider the consequence of double jumping and exactly how high you had to jump.
Notable examples (Creativity): Spinning Laser Trap (Extra bonus is it was awesome to look at), "Hidden" platform room (gray backround with outlines appearing only when you jump), Pacman.
Notable examples (Timing and Height): A hall of saws, Pit of Death, and the white/black platform section.
A final couple of notes, the Video Game cameos were well-chosen (Well known, but not predictable or overplayed, do that in the sequel please!) and the music was fast and interesting. Finally, the shooting wasn't overplayed or annoying when you introduced it, and the Battletoads wheel-race was fun (but should have been made more obvious as a reference somehow. If it wasn't a reference and was, in fact, an original idea, e-mail me so I can explain).
So, why only 9 stars? Well, I don't review often, and if I'm going to review something great, I'm not going to do it without finding a way to make the next one even better. You obviously did a lot of testing to avoid things like this, and there were really only a couple of problems, but they did stand out.
Mount Poo: I never found defecation to be as funny as some, but that's not the complaint. The complaint is that you can't dodge the poo if it's aimed at you (it's just not possible) and it flies in random directions. While most of the game was memorization or skill, we come to a frustrating random bit. Even a very difficult pattern would have been better here. Similarly, the "Three Bloody Spikes" jumping suffered a similar problem. Also, the room with the tiny yellow platforms with spikes on the walls (with the hysterical extra-large spike) really pushed the difficulty/random factor, so that one is borderline.
Final Boss Spikes: These should have been slightly slower and more frequent/random, causing you to plan a path to avoid them. As it ended up, I just found a spot where they almost never fell on the top platform and killed my "E" key, which made the fight less entertaining.
Flashing Lights: While entertaining (for a little bit) during the Pacman part, and effective at distracting my jumping, it still hurt my eyes (no fun) and could be a SERIOUS problem for people with epilepsy.
The Music: Yes, I already said the music was good. The problem? Every time you die the music resets, and the beginnings to a couple of the songs were boring/repetitive, and eventually became more annoying than fun. Also, some great songs never got fair treatment, because you couldn't hear the full song with it re-started every life. For a good example, the "Huge Spike in the Pit" room and song fits this situation perfectly.
So, again, overall I absolutely loved this. Enough to stop and let you know about it. I am greatly looking forward to a sequel, so don't disappoint! Hope my feedback helped, and feel free to contact me with additional questions.