Droid Assault

Excellent game with incredibly good graphics and sound design, as well as a vast variety of enemies that you can control. While its story is relatively nonexistent, its arcade-style gameplay is addictive and strategic. Its main issues are technical ones from the engine getting long in the tooth and unable to support modern controllers and resolutions, though it also suffers from bad hitboxes in some cases, iffy balancing between levels, and annoying flicker effects. Nevertheless, it's worth the price of admission due to its very solid and fun core gameplay, and luckily you don't have to restart from scratch if you lose, as there are handy checkpoints throughout.