It is considered a budget multimedia card. It's not until you get to the Radeon HD 5670 where you have something that is considered a mainstream graphics card for games.
The HD 5450 can be used to play some recent games, but you better have low expectations. It is also too slow to effectively use 1GB of RAM in games. Even the much faster HD 5670 gains very, very, very little performance increase with 1GB of RAM vs. only 512MB of RAM.