Fortix is a fun casual game. Use your mouse or keyboard and draw a path to cover up the map. Within your box you can kill dragons/bats and take down towers. Or you can collect arms within your drawn box to activate catapults to take down the towers. This game is super simple, but can get extremely difficult if you play on the impossible difficulty level. Worth a play

This game reminds me of the old Rampart game

This reminds me of a Sega Megadrive/Genesis game - a version of which was also found in Arcades - however the name eludes me right now.

In it you would go around in a spaceship fighting aliens and going deeper down the layer of various planets.