Single player, by 
Before I start this review, a short note to the author: Please don’t take this review personal, I don’t write it because I am mean or something, I write it so you know what’s wrong and how to improve your levels.
For a first level, this isn’t too bad (I’ve seen far worse). It has, however, several problems. The first one is that it is way too short. After killing a few baddies and collecting some ammo you get warped into the boss arena, where you fight the Robot. After that the level ends. I think it took me 1 or 2 minutes to play through this, a good level should take at least 10 minutes of length. The second problem is that it is way too easy. The robot boss was never really hard to beat, and the few baddies don’t really add a challenge either. When making Single Player levels, always try to give the enemies an advantage. For example, look at the bat. What things can the bat do which Jazz can’t? It can fly, and it can fly “through” walls. If you now place a bat under the floor Jazz has to be quick to buttstomp it before the bat gets him. Also tone down on carrots and goodies. Always think to yourself: Does the player need the goodie I’m going to place? If you can beat the robot without a full energy carrot, then don’t place one. Third problem: Creativity. The only thing you do is run around, collect ammo, kill baddies and shoot the boss to pieces. Try doing something which hasn’t been there before. A good idea would be to make a puzzle. Puzzle’s always add a nice touch to a level, and there are endless possibilities. Problem number four is Eyecandy. The tileset you have used is a little crappy, the tiles look ugly and I often couldn’t tell the difference between the background and solid tiles. There are plenty of good tilesets around here at J2O, search a little and you’ll find one which suits you. The last problem is the lack of story. There is absolutely no point of killing those enemies and the robot, no goal, nothing which keeps the player trying to win to see how it ends. A story doesn’t have to be complicated, a simple reason why you’re doing the stuff you do is enough in most cases to get a decent level. It shouldn’t be as dull as “Devan is back and you have to stop him!” though.
I hope this helps you to improve your skills, just keep trying and you’ll become better. ;)
Download Recommendation: No
