Nebulus was one of my favourite games on my good old Commodore 64 and for this PC-Version I cannot say anything about major deficites (except the graphics).
You are a small green pig-like alien and have come in your Mk.7 submarine to destroy seven towers. To do so you need to climb to the top of each and that turns out to be much harder than it sounds.
First enemy is time. Once you made your way to almost the top of a tower it runs out and you need to restart at the very beginning. Secondly, enemy is a green thing that appears every now and then just to throw you off your current position one or two stories down. The remaining enemies are just decoration. Run under the evil eyeball, shoot at balls to stop or destroy them and avoid loose bricks. You use the elevators and doors to find your way up and there you are – almost done – bang – the green spinning thing hit you and threw you back to the beginning ... grmpf. I really do have to say that it can make you quite angry (especially when you write a review and are in need to take some good screens).
The controls are very good when you use the joystick. If you don't, you maybe want to map your keyboard with DOSBox in order to play this game with fun or maybe you like playing with „o“ for left, „p“ for right, „“q“ for up and „a“ for down with the space bar to jump and shoot. However I strongly recommend the joystick.
The sounds are described like this: no music. Some very unspecial sound effects that do their job but nothing beyond.
Is there more to say else than: „Come on and try it!“ ?