On first play this is sort of a fun game. It works pretty much like any car race program and therein lies the issue. If anyone who made this ever actually watched a horse race, they'd know that a. the fastest way around a racing oval is the rail (yet this game seems to take off time if you do that), b. Horses have to stay in their lanes (not go all over the place as they do here, blocking willy nilly, which would earn them a disqual in real racing) and c. Horses don't race on the outside and then zoom in to the inside around a corner the way a race car does (See a and b for why not).
Moreover, the races seem rigged if you are in even company to favor front runners. If you get out ahead and you have the right rating, odds are good you will win. If you do try to stalk or come from behind, it's nearly impossible to rate your speed to where you don't either fall way behind or pass.
There's no attempt made to make the distances at all like racing. one, two or three laps is car racing talk, not horse racing. There's no weight differences for handicapping. And it makes no sense to me that the cost to breed goes up over time.
All said, if these were cars or motorcycles, I'd say fun game. For horse racing, it completely misses the mark.