There was the set of parts for one big education project for the company Escape Educatief (Netherlands). The projects was next:
http://www.getafreelancer.com/projects/Delphi/Delphi-project-for-YetiDi-only.html
http://www.getafreelancer.com/projects/Delphi/Project-for-YetiDI.html
http://www.getafreelancer.com/projects/Delphi/Delphi-project-YetiDi-only.html
http://www.getafreelancer.com/projects/Delphi/Delphi-graphical-fraction-composition.html
http://www.getafreelancer.com/projects/Delphi/Delphi-project-for-Yetidi-Only.263300.html
http://www.getafreelancer.com/projects/Delphi/puzzle-game-for-YetiDi.html
http://www.getafreelancer.com/projects/Delphi/Fraction-lessons-for-Yetidi-only.html
http://www.getafreelancer.com/projects/Delphi/cutting-bars-circles.html
Delphi + Geometrical computations = game for children
This is a very simple description of these games.
In most of them the very complex 2D vector graphic is used.
Fraction preview – simple calculations and geometric
Lesson1 – EMW/WMF-support, the form looks the same in any resolution
Lesson3 – nothing interesting just calculations
Lesson6 – similar to Lesson1, many calculations
Lesson7 – the WMF-animation (based on Timer), dividing of circles into any quantity of parts
Puzzle Game – extremely complex computation geometry with polygons and areas; TPaintbox operations are used instead of standard Delphi's TImage
Fraction Calculation – looking very nice, many calculations
Cutting Game – flexible polygon areas, TPaintBox 2D-graphic optimization, most powerful module from all Fraction Games