While on it's surface it may look like a simple game, the lore in Sleengster is on par with, if not better than, the lore of the Dark Souls series or The Elder Scrolls series. Heck, even the store description is deep:

There's trouble in Sleengville!

The villagers are being under attack by the terrible Tikkirama organization. They are in search for the legendary Great Portal Gems. Our hero, Sleengster, must find all the gems in every part of the Village before the bad guys do. Your job is to pass through 30 different stages in search for the Gems. On your quest, you will encounter various enemies, not only Tikkirama, but every scumbag creature in Sleengland that was willing to join the Tikkirama cause. But you are not helpless! On your journey, you will be helped by Digital PC Gentlemen who will help you keep your progress. Also, you will have a quite nice range of weaponry hidden throughout stages, but save your ammo! Collect Sleengcoins along the way to unlock additional stages and get awards.

I don't think I'd be alone in saying that Sleengster is basically the Citizen Kane of gaming.

I think one of the best parts of Sleengster is the achievements. They are pretty difficult and require a lot of practice and skill to get, but you must get them if you want to be a Sleengster pro like me.

How to get them are as follows:

Shooter 1: Probably the hardest, but press the "f" key once.
Shooter 2: Do that one more time.
Shooter 3: Do that one more time.
Shooter 4: Do that one more time.
Shooter 5: Do that one more time.
Shooter 6: Do that one more time.
Shooter 7: Do that one more time.
Shooter 8: Do that one more time.
Shooter 9: Do that one more time.
Shooter 10: Do that one more time.
Shooter 11: Do that one more time.
12-428: Just keep pressing "f".