Just had a pretty good idea for levels.Clear the screen, change the player size and show a number to indicate the level. This gives a clean break between levels.For each level, set the ooze difficulty to some value. Set the colors and set the gametime (was fuel.)Use some of the powerups to make the levels interesting and varied.Slow bullets, slow oozeFast bullets, really fast ooze.Use the target to trigger other avaliable powerups and to add game time on last level, otherwise game has a specific end. Level 10.Have one of the targets place some random unshootable ooze drops on the screen for extra fun. This is a bug, but one that can be a game feature if used correctly.Maybe play some goofy music between levels. Make level 8 really tough. Push the player to their limits, keep target time short in order to put pressure on. Target is 50 / 50 adds to game time, slows ooze. (Hehe.)Store level encodings as data statements, for rules and to set the various game mode bits.Have to edit the whole fuel section of the program and get rid of the low fuel ship indicator... maybe keep it to let very busy player know they are almost through with a tough level...I have always liked pure survival games. However, most games these days have an end to them, so split the middle. Game ends at level 10, but targets can be shot to extend gametime. Target onscreen time gets shorter and shorter until only super-human player can get them.